tk_optionMenu
Makes a button, which when clicked on shows a list with available options. Useful when user has to make one choice when multiple choices are given. Below is a options menu in HTML. A word of caution though - Tcl/Tk's option menu has a very different appearance.
Syntax
tk_optionMenu path varName value ?value value ...?
Example...
set opt "Two" tk_optionMenu .omn opt "One" "Two" "Three" "Four" "Five" "etc." pack .omn