i have a textarea that i want to be as wide as the window (100%). i have to add the attribute cols for the code to validate but if i do add it i don't get the full width on all screens. i tried with css (width:100% but that didn't do anything (at least not on my ericsson s700). any ideas how to get this to work?

my other question is:
i have a header picture that i also always want to be as wide as the screen. how should i solve that? is there a way to check the screen width and then load different images? or should i have just one image that i stretch/shrink?

any ideas on this two things would be great! thanks!