How to change the backbround image of welcome page

Hey , anyone can help me , as i want to change the back ground image of Welcome page..As i am using this " !insertmacro MUI_PAGE_WELCOME "..with this i am getting the default welcome page, but i need to change the background image of welcome page so that we can add our own images.So please reply for this Nsis setup..i am sending an attachment also with it.

Just define it in MUI_WELCOMEFINISHPAGE_BITMAP before the welcome page macro

!define MUI_WELCOMEFINISHPAGE_BITMAP "${NSISDIR}\Contrib\Graphics\Wizard\yo.bmp"

!insertmacro MUI_PAGE_WELCOME