I wish to have each page of a tab control be used with a subvi. One for graphs, one for data entry,etc and wish to have the tab page number start and stop the selected subvi. Up until now I have been using 'run on open' and a seperate stop button for each subvi. I tried creating dummy tab pages and local variables and it works but is clunky. The problem is that I can't read a tab page number selected from a main program while I'm in a subvi. Thanks, Jim W