diff --git a/python/2d_event_display_server.py b/python/2d_event_display_server.py
index 0c6784f..cc19a99 100644
--- a/python/2d_event_display_server.py
+++ b/python/2d_event_display_server.py
@@ -1,20 +1,39 @@
-import os
+"""
+Interactive 2d event display for text digitization files for tdis
+One needs to 'pip install bokeh numpy' to use it
+How to use:
+  > bokeh serve --show 2d_event_display_server.py --args track_data.txt
+
+With IDEs
+If you use it in IDEs like CLion or PyCharm one can use
+  Module: bokeh
+  Command line options: "serve --show 2d_event_display_server.py --args  track_data.txt"
+"""
+
+import sys
 import math
 import numpy as np
 from bokeh.plotting import figure
-from bokeh.models import ColumnDataSource, Slider, Select, Button
+from bokeh.models import (
+    ColumnDataSource, Slider, Button, TextInput, Div,
+    CategoricalColorMapper
+)
 from bokeh.layouts import column, row
 from bokeh.io import curdoc
+from bokeh.palettes import Category10_10
+
 
 # Constants
 num_rings = 21
 num_pads_per_ring = 122
 first_ring_inner_radius = 5.0  # Minimum radius in cm
-max_radius = 15.0         # Maximum radius in cm
+max_radius = 15.0              # Maximum radius in cm
 total_radius = max_radius - first_ring_inner_radius  # Total radial width (10 cm)
-ring_width = total_radius / num_rings   # Radial width of each ring
-delta_theta = 2 * math.pi / num_pads_per_ring  # Angular width of each pad in radians
-plane_spacing_cm = 55.0 / 10  # 55 cm total length, 10 planes, so 5.5 cm per plane
+ring_width = total_radius / num_rings                # Radial width of each ring
+delta_theta = 2 * math.pi / num_pads_per_ring        # Angular width of each pad in radians
+plane_spacing_cm = 5.0  # Plane spacing is 5 cm
+filename = 'track_data.txt'  # Default filename if no script arguments are provided
+
 
 def get_pad_center(ring, pad):
     """
@@ -28,10 +47,7 @@ def get_pad_center(ring, pad):
     # Compute radial center of the ring
     r_center = ring_width * (ring + 0.5) + first_ring_inner_radius
     # Determine the angular offset for odd rings
-    if ring % 2 == 0:
-        theta_offset = 0  # Even rings
-    else:
-        theta_offset = delta_theta / 2  # Odd rings
+    theta_offset = 0 if ring % 2 == 0 else delta_theta / 2
     # Compute the angular center of the pad
     theta_center = delta_theta / 2 + pad * delta_theta + theta_offset
     # Convert from polar to Cartesian coordinates
@@ -41,10 +57,10 @@ def get_pad_center(ring, pad):
 
 def read_track_data(filename):
     """
-    Read the track data from a file and return a list of events.
-    Each event is a dictionary with keys: 'event_number', 'track_params', 'hits'.
+    Read the track data from a file and return a dictionary of events.
+    Each event is a dictionary with keys: 'track_params', 'hits'.
     """
-    events = []
+    events = {}
     with open(filename, 'r') as f:
         lines = f.readlines()
     i = 0
@@ -65,12 +81,10 @@ def read_track_data(filename):
                     hit_data = list(map(float, hit_line.split()))
                     hits.append(hit_data)
                 i += 1
-            event = {
-                'event_number': event_number,
+            events[event_number] = {
                 'track_params': track_params,
                 'hits': hits
             }
-            events.append(event)
         else:
             i += 1
     return events
@@ -84,6 +98,7 @@ def prepare_hits_data(hits):
     hit_ys = []
     hit_zs = []
     amplitudes = []
+    planes = []
 
     for hit in hits:
         # Unpack hit data
@@ -103,13 +118,15 @@ def prepare_hits_data(hits):
         hit_ys.append(y)
         hit_zs.append(z_hit_cm)
         amplitudes.append(amplitude)
+        planes.append(f"Plane {plane}")
     # Convert lists to numpy arrays
     hit_times = np.array(hit_times)
     hit_xs = np.array(hit_xs)
     hit_ys = np.array(hit_ys)
     hit_zs = np.array(hit_zs)
     amplitudes = np.array(amplitudes)
-    return hit_times, hit_xs, hit_ys, hit_zs, amplitudes
+    planes = np.array(planes)
+    return hit_times, hit_xs, hit_ys, hit_zs, amplitudes, planes
 
 def prepare_background_geometry():
     """
@@ -123,7 +140,7 @@ def prepare_background_geometry():
         for pad in range(num_pads_per_ring):
             x, y = get_pad_center(ring, pad)
             for plane in range(10):
-                z = plane * plane_spacing_cm
+                z = plane * plane_spacing_cm  # Adjusted plane positions
                 pad_xs.append(x)
                 pad_ys.append(y)
                 pad_zs.append(z)
@@ -133,78 +150,188 @@ def create_plots(events):
     """
     Create the plots and return the layout.
     """
-    # Prepare background geometry
+    # Prepare background geometry for XY plot (unchanged)
     pad_xs, pad_ys, pad_zs = prepare_background_geometry()
-
-    # Create ColumnDataSource for background pads
     background_source_xy = ColumnDataSource(data=dict(x=pad_xs, y=pad_ys))
-    background_source_zy = ColumnDataSource(data=dict(z=pad_zs, y=pad_ys))
 
     # Create empty ColumnDataSource for hits
-    source_xy = ColumnDataSource(data=dict(x=[], y=[]))
-    source_zy = ColumnDataSource(data=dict(z=[], y=[]))
-    all_hits_source = ColumnDataSource(data=dict(x=[], y=[], z=[], time=[]))
+    source_xy = ColumnDataSource(data=dict(x=[], y=[], plane=[]))
+    source_zy = ColumnDataSource(data=dict(z=[], y=[], plane=[]))
+    all_hits_source = ColumnDataSource(data=dict(x=[], y=[], z=[], time=[], plane=[]))
 
     # Create figures
-    p_xy = figure(title="Track Hits in TPC Detector (X vs Y)", x_axis_label='X Position (cm)', y_axis_label='Y Position (cm)', width=600, height=600,
-                  match_aspect=True)
-    p_zy = figure(title="Track Hits in TPC Detector (Z vs Y)", x_axis_label='Z Position (cm)', y_axis_label='Y Position (cm)', width=800, height=600)
+    p_xy = figure(title="Track Hits in TPC Detector (X vs Y)", x_axis_label='X Position (cm)',
+                  y_axis_label='Y Position (cm)', width=600, height=600, match_aspect=True)
+    p_zy = figure(title="Track Hits in TPC Detector (Z vs Y)", x_axis_label='Z Position (cm)',
+                  y_axis_label='Y Position (cm)', width=800, height=600)
 
-    # Plot background pads
+    # Plot background pads for XY plot (unchanged)
     p_xy.circle('x', 'y', size=2, color='lightgrey', alpha=0.3, source=background_source_xy)
-    p_zy.circle('z', 'y', size=2, color='lightgrey', alpha=0.3, source=background_source_zy)
 
-    # Plot hits
-    p_xy.circle('x', 'y', size=6, color='blue', source=source_xy)
-    p_zy.circle('z', 'y', size=6, color='red', source=source_zy)
+    # Define color mapper for planes
+    planes_list = [f"Plane {i}" for i in range(10)]
+    color_mapper = CategoricalColorMapper(factors=planes_list, palette=Category10_10)
+
+    # **New Code: Prepare background rectangles for ZY plot**
+    x_centers = []
+    y_centers = []
+    widths = []
+    heights = []
+    planes_bg = []
+
+    Y_min = -max_radius
+    Y_max = max_radius
+    y_center = 0
+    height = Y_max - Y_min  # Total height covering the detector in Y
+
+    for plane in range(10):
+        z_plane = plane * plane_spacing_cm
+        x_center = z_plane  # Center of the plane in Z
+        width = 0.5  # Width equal to plane spacing
+
+        x_centers.append(x_center)
+        y_centers.append(y_center)
+        widths.append(width)
+        heights.append(height)
+        planes_bg.append(f"Plane {plane}")
+
+    background_rect_source = ColumnDataSource(data=dict(
+        x=x_centers,
+        y=y_centers,
+        width=widths,
+        height=heights,
+        plane=planes_bg
+    ))
+
+    # **Plot background rectangles in ZY plot**
+    p_zy.rect('x', 'y', 'width', 'height', source=background_rect_source,
+              fill_color={'field': 'plane', 'transform': color_mapper},
+              line_color=None, fill_alpha=0.1)
+
+    # **Remove the old background pads in ZY plot**
+    # (Comment out or delete the following line)
+    # p_zy.circle('z', 'y', size=2, color='lightgrey', alpha=0.3, source=background_source_zy)
+
+    # Plot hits with colors based on plane
+    hits_xy = p_xy.circle('x', 'y', size=6, source=source_xy,
+                          color={'field': 'plane', 'transform': color_mapper}, legend_field='plane')
+    hits_zy = p_zy.circle('z', 'y', size=6, source=source_zy,
+                          color={'field': 'plane', 'transform': color_mapper}, legend_field='plane')
+
+    # Adjust legends (unchanged)
+    for plot in [p_xy, p_zy]:
+        plot.legend.title = 'Planes'
+        plot.legend.location = 'top_right'
+        plot.legend.click_policy = 'hide'
+
+    # Rest of the code in create_plots remains unchanged...
+
 
     # Create time slider
     time_slider = Slider(start=0, end=1, value=0, step=0.1, title="Time (ns)")
 
-    # Create event selector
-    event_numbers = [str(event['event_number']) for event in events]
-    event_selector = Select(title="Select Event:", value=event_numbers[0], options=event_numbers)
+    # Create event number input and buttons
+    min_event_number = min(events.keys())
+    max_event_number = max(events.keys())
+
+    event_number_input = TextInput(title="Event Number:", value=str(min_event_number), width=100)
+    show_button = Button(label="Show", button_type="success", width=60)
+    next_button = Button(label="Next Track", button_type="primary", width=80)
+
+    # Create event limits display
+    event_limits_div = Div(text=f"File {filename} has events: {min_event_number} to {max_event_number}", width=300)
+
+    # Arrange controls
+    controls = row(event_number_input, show_button, next_button, event_limits_div)
+
+    # Keep track of the current event index and event numbers
+    event_numbers = sorted(events.keys())
+    current_event_index = 0  # index into event_numbers list
+
+    # Define the function to load event data
+    def load_event_data():
+        nonlocal current_event_index
+        # Get the event number from the input
+        try:
+            selected_event_number = int(event_number_input.value)
+        except ValueError:
+            print(f"Invalid event number: {event_number_input.value}")
+            return
+
+        if selected_event_number in events:
+            selected_event = events[selected_event_number]
+            current_event_index = event_numbers.index(selected_event_number)
+        else:
+            print(f"Event number {selected_event_number} not found.")
+            return
 
-    # Define the callback to load event data
-    def load_event_data(attr, old, new):
-        # Get the selected event
-        selected_event_number = int(event_selector.value)
-        selected_event = next(event for event in events if event['event_number'] == selected_event_number)
         hits = selected_event['hits']
         # Prepare hits data
-        hit_times, hit_xs, hit_ys, hit_zs, amplitudes = prepare_hits_data(hits)
+        hit_times, hit_xs, hit_ys, hit_zs, amplitudes, planes = prepare_hits_data(hits)
         # Update all_hits_source
-        all_hits_source.data = dict(x=hit_xs, y=hit_ys, z=hit_zs, time=hit_times)
-        # Update time slider range
+        all_hits_source.data = dict(x=hit_xs, y=hit_ys, z=hit_zs, time=hit_times, plane=planes)
+        # Update time slider range and set to maximum time
         time_slider.start = hit_times.min()
         time_slider.end = hit_times.max()
-        time_slider.value = hit_times.min()
+        time_slider.value = hit_times.max()  # Show all hits initially
         # Update the plots
         update_plots(None, None, None)
 
-    event_selector.on_change('value', load_event_data)
+    # Define the callback for the "Show" button
+    def on_show_button_click():
+        load_event_data()
+
+    show_button.on_click(on_show_button_click)
+
+    # Define the callback for the "Next Track" button
+    def on_next_button_click():
+        nonlocal current_event_index
+        current_event_index += 1
+        if current_event_index >= len(event_numbers):
+            current_event_index = 0  # Loop back to the first event
+        selected_event_number = event_numbers[current_event_index]
+        event_number_input.value = str(selected_event_number)
+        load_event_data()
+
+    next_button.on_click(on_next_button_click)
 
     # Define the callback to update plots based on time slider
     def update_plots(attr, old, new):
         current_time = time_slider.value
         data = all_hits_source.data
         mask = data['time'] <= current_time
-        source_xy.data = dict(x=np.array(data['x'])[mask], y=np.array(data['y'])[mask])
-        source_zy.data = dict(z=np.array(data['z'])[mask], y=np.array(data['y'])[mask])
+        source_xy.data = dict(
+            x=np.array(data['x'])[mask],
+            y=np.array(data['y'])[mask],
+            plane=np.array(data['plane'])[mask]
+        )
+        source_zy.data = dict(
+            z=np.array(data['z'])[mask],
+            y=np.array(data['y'])[mask],
+            plane=np.array(data['plane'])[mask]
+        )
 
     time_slider.on_change('value', update_plots)
 
     # Initial load of event data
-    load_event_data(None, None, None)
+    load_event_data()
 
     # Arrange layout
-    layout = column(event_selector, row(p_zy, p_xy), time_slider)
+    layout = column(controls, row(p_zy, p_xy), time_slider)
     return layout
 
-# Read the track data from the file
-filename = 'D:\\data\\tdis\\g4sbsout_EPCEvents_200000.txt'  # Replace with the actual filename
 
-print("Reading events...")
+
+
+# bokeh serve set sys.argv for the script. I.e.
+# If command line is:
+# bokeh serve --show 2d_event_display_server.py --args track_data.txt
+# Then sys.argv for this script will be
+# ['2d_event_display_server.py', 'track_data.txt']
+if len(sys.argv) > 1:
+    filename = sys.argv[1]
+
+print(f"Reading events from file: {filename}")
 events = read_track_data(filename)
 print(f"Loaded events: {len(events)}")
 
diff --git a/use_docker.md b/use_docker.md
index c8ddbf8..4f17999 100644
--- a/use_docker.md
+++ b/use_docker.md
@@ -31,7 +31,10 @@ docker pull eicdev/tdis-pre
 Running docker (minimal and probably useless):
 
 ```bash
-docker run -it --rm eicdev/tdis-pre
+docker run -it --rm eicdev/tdis-pre 
+
+# like run bash shell in docker
+docker run -it --rm eicdev/tdis-pre bash
 ```