problem in watermarking an image - HTML exporting

Dear All,

                         I have user Ireport 3.7.4 ,I used the Background band ,There i use my image as background ,When i run as PDF ,it works fine but when i run as HTML there is no Back Ground image available.

please help me to fix this problem. Also pls suggest me if any other option for watermarking an image in HTML exporting..

Thanks,

Elango