how to access axes handle in other callback functn?

hello,, i got the problem with displaying image on axes. in my gui, der r 2 axes, and 4push buttons. 1st axes takes input image. it ll b processed n reultin image shud b displayed in 2nd axes, wen i clik on any button. i gav abov mentioned lines in callbak fun of button to access 2nd axes. bt it is showin error 'access to non existent handles.axes2' my axes tag is axes2 itslf. plz help me out in solvin dis...