Had gone through the steps which were mentioned out in Cisco guide line like
1)resized the pictures in 320*212 and 80 * 53 pixels
2) there was no list.xml file as default.so i have created the list.xml file and uploaded in software upgrades path.
3)uploaded the pictures also in the same path
4) restarted the tftp service
5)when i tried to see the pictures in phones,only default picture was there.
Dudes,pls guide me whether i have missed out any steps.If so,pls put it in detail.