Free Memory Block


                 This function  frees a  memory block  that was allocate
                 through the allocate memory block function.

            To Call

                 AX = 0502h
                 SI:DI = Handle of memory block to free

            Returns

                 If function was successful:
                 Carry flag is clear

                 If function was unsuccessful:
                 Carry flag is set

            Programmer's Notes

                 o    Your program  must also free any selectors that it
                      allocated to point to the memory block.