;+
; NAME: stackpush
;
; PURPOSE: 
;	pushes a variable onto a stack. If the stack is undefined, it is
;	created.
; NOTES:
;            stackpush,stack,var
;		see also stackpop.pro
;		
; INPUTS:
; KEYWORDS:
; OUTPUTS:
;
; HISTORY:
; 	Began 2002-04-01 00:48:36 by Marshall Perrin 
;-

pro stackpush,stack,var
	checkargnum,n_params(),2,"stackpush,stack,var"

	if n_elements(stack) gt 0 then $
		stack = [stack,var] $
	else $
		stack=[var]

end