trigger popup message from asp menu item

Question

I have a menu in asp with many menuitems. I want one of the menu items to call a popup box.

I am using C# with code in a seperate file.

I would normally say something like:

RegisterStartupScript("Format Error", "<script>alert('Max Load Must be an Integer')</script>");

I want this to be called when I click the Menu Item.

The idea is that this can display an About Message box with like version in formation on it and other stuff...

Can this be done?

Thanks!