ByVal

Whats ByVal Mean??

Byval=By Value
A way of passing the value, rather than the address, of an argument to a procedure. This allows the procedure to access a copy of the variable. As a result, the variable's actual value can't be changed by the procedure to which it is passed.

You should be able to find a good answer to that in any beginners programming book. Look for passing parameters by value or by reference.

Simply put, ByVal means by value and it basically creates a new variable for use locally within the function and does not affect the actual variable that was passed in. ByRef means by reference and it actually passes the physical memory address of the variable and does all of it's work directly on that variable.