The BITSET() function turns on a specified bit in an integer value.
The BITSET() function converts expr to a 32 bit integer and turns on (sets to 1) the bit identified by bit to form a new integer value as the result. Bits are numbered from 0 to 31 from the least significant end of the value. The effect of this function with a bit value outside this range is undefined.
FLAGS = BITSET(FLAGS, 2)
This statement turns on bit 2 in the FLAGS variable.