edited image not being saved and displayed properly

[SUBSCRIBE MAPSERVER-USERS mapuser]

i have got a bit success in going through the interactive html page. i 
have used exampe1-9 of the tutorial, which is working fine, but as 
soon as i change the map file to my own data, then i get the full image 
only once i.e. at the time of first load. as soon as i click the image at 
any location, i get a blank image, and that is what is saved in the tmp 
directory, a blank image.

why my new image is not being saved and displayed, can anyone 
please help.
thanks.