Transparent Image overlapping

Hi,
I am php programmer. I am getting trouble in overlapping transparent images.

Meas if I have to overlap small image on big image it shows white area around small image or transparent area(if I explicitly made it transparent).

can any body help me in this situation?

Thanks in advance.

Rohit, for that purpose you need to make one container which needs to be transparent.
And then merge all those transparent images in that container.
I think it should work.