Menu Action from Form's Private Sub

I have created a new menu bar in MS Access 2002. In the "On Action" section for customizing a particular menu item, I have no problem running a Macro or running a function from a program module. However, I would like to run the code that is behind a particular button in the form (savebutton_click)--a private sub for a click. All I get is an error saying that the program cannot find the the function name. Any suggestions?