; This function checks for existence of a given tag within a structure.
;
; Parameters:
; structure     data structure
; tag           name of the tag to search for
;
; Returns:
; true          if tag exists
; flase         otherwise
;
; History:
; 24.10.2015, PABourdin: coded

function has_tag, structure, tag

	COMPILE_OPT IDL2, HIDDEN

	return, (find_tag (structure, tag) ge 0)
end