Transparency in dreamweaver

Hello, i just made a image on photoshop 500 x 500 with some squares and shadows , my background is transparent and i saved it as PNG… i need the transparency becuase of my html page that has another image as background if i don’t have it that way my image would be on top of my background and would see darker… now when i insert my image on my design section it looks good… transparent and everything but when i hit the f12 to view the preview the background of my image goes blue… and im no even using blue… im using. green white and black… so any ideas so my image can work ??
thanks. :slight_smile: