diff --git a/tk/button.go b/tk/button.go
index 96e3d78..fd03867 100644
--- a/tk/button.go
+++ b/tk/button.go
@@ -46,6 +46,10 @@ func (w *Button) Text() string {
 	return r
 }
 
+func (w *Button) SetUnder(pos int) error {
+        return eval(fmt.Sprintf("%v configure -under %d",w.id,pos))
+}
+
 func (w *Button) SetWidth(width int) error {
 	return eval(fmt.Sprintf("%v configure -width {%v}", w.id, width))
 }