FUNCTION ibclrf, bitset, bitpos

;+
; NAME:
;	ibclrf
; PURPOSE:  
;	Takes a longword (32-bit) integer, and clears (sets to zero) a bit
; CATEGORY:
;	Bits and bytes
; CALLING SEQUENCE:
;	Result = ibclrf(bitset, bitpos)
; INPUT:
;	bitset	longword	A longword integer, one of it
;				bits will be clear or zero 
;	bitpos	longword	The position of the bit that
;				will be cleared; 0 <= bitpos <= 31
; OUTPUT:
;	Result 	longword	Same as bitset, (bitwise) but
;				at bit position, bitpos, it will
;				definitely be a zero
; INCLUDE:
	@compile_opt.pro	; On error, return to caller
; SEE ALSO:
;	ibsetf, ibtestf
; MODIFICATION HISTORY:
;	8/23/00			Kevin Nguyen
;-
RETURN, bitset-(bitset AND ishft(1L, bitpos))
END