the issue here is GUI dependancy;
you've got to get used to using the TSQL window for your commands, instead of using the GUI tools.
if you right click on a procedure, you get a form where you can enter the values for the parameters for the given procedure;
it's much easier to simply use TSQL to do that instead.
here's an example, showing both methods at the same time.
note that after you populate the values for the parameters, if you click the "Script" icon in the upper left of the window, you can get a TSQL window built for you automatically.
Lowell