Call another page after the menu had been selected

Dear all I'm using UltraDev which build a form containing a menu, there a two items inside this menu for user to choose. This form is using Post Action to $php_self which means it will pass back the variable to itself. Then here is the question: what should i do if i want to call a page prompt from a blank window when the item A is selected? and another page when Item B is selected! thx a lot jack jack@nedcor.com