This information is taken straight from the Visual Basic Help:
A Sub procedure differs from a Function procedure in that a Sub procedure cannot be called by using its name within an expression. A call to a Sub is a stand-alone statement. Also, a Sub does not return a value in its name as does a function. However, like a Function, a Sub can modify the values of any variables passed to it.
There are two ways to call a Sub procedure:
Note that when you use the Call syntax, arguments must be enclosed in parentheses. If you omit the Call keyword, you must also omit the parentheses around the argumentsCode:' Both of these statements call a Sub named MyProc. Call MyProc (FirstArgument, SecondArgument) MyProc FirstArgument, SecondArgument
Hope that helps