showing flash or .gif..please help

[webon]

I have a flash banner in my page header and i would like that when the internet browser used doesn't have macromedia flash instaled shows a gif image instead.
I mean, having two possible banners and depending the browser flash support or not, the site automaticaly shows a flash version or a gif version of the header respectively.

Is that possible??
Do any of you know a script or code to do that??

as for the records I'm programing in php...

thanks in advance

webon

[Wojtek]

Try layers

build the normal thing with the .gif
then in html make a layer and position it exactly over the gif so the flash matches

google html layers, I think that should work