Tcl is a scripting language quite a bit different from ruby, tk is a GUI extension to that scripting language that has been picked up by other scripting languages as well to serve as their own GUI extension (for more on Tcl/Tk directly, see http://www.tcl.tk). I could answer this question in Tcl by saying that the tile widget set in Tk 8.5beta supports comboboxes, however I doubt that Ruby/Tk is that up-to-date with respect to Tk versions. Now ComboBox spelled in that way is a BWidget widget (a 'megawidget set' that is an add on to Tk). Ruby/Tk at http://rubytk.jurijveresciaka.com/ says you make this by doing: Tk::BWidget::ComboBox.new(root) I believe to use this you'll have to get the BWidget extensions installed to your Tk installation. See e.g. http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/143351 If you can tell me what operating system/distribution you are running on I could probably help you figure out how to do that. Feel free to contact me off line if you prefer, as this is probably wandering a bit off topic for the list (into the realm of Tcl/Tk from Ruby). Ron Fox lote wrote: > Hi everbody, i am newest at the Ruby/tk and i want to do something..i > want to use ComboBox but default tk does not contain combobox control. > How can i use it ? and What is the difference between TCL and TK ?? > > thanks... >