BITCHECK returns the current value of a specified bit from the local bit table.
table_no specifies the position in the table of the bit to be checked.
A unique table of 128 bits (numbered 1 to 128) is maintained for each process. Each bit in the table is treated as a two-state flag - the value returned will always be 0 (zero) or 1.
BITCHECK also provides some special functions if you use one of the following table_no values:
If bit 100 in the table is 0 (zero), 0 will be displayed. If bit 100 is set to 1 (one), 1 will be displayed.