instead of using a button i use an icon and then set my coding for it .....i use mdx
example :
box "controls", 1, 1 0 511 39
icon 2, 16 8 32 10, $mircdir\icons\start.jpg, 0, noborder
on *:dialog:cont:sclick:2:{ /update -s }
you can set sclick , rclick , and dclick
hope this helps