Another way for a subroutine or function to receive arguments is with the ARG built-in function. This function returns the value of a particular argument. A number represents the argument position.
ARG length, width
you can use the ARG function as follows:
length = ARG(1) /* puts the first argument into length */
width = ARG(2) /* puts the second argument into width */
For more information about the ARG function see section ARG.