I'm trying to freeze my header at the top of the page while scrolling - the only thing I found was the following from another thread, which I inserted at the bottom of my style sheet but it didn't work -

.main_block {
height: 241px; overflow-y:scroll;
}

I obviously don't know what I'm doing here, can someone help me with the correct coding to make it do this, please.

Thanks once again, you guys always bail me out!!!!! You've been such a help on this site, thanks to you, I'm getting closer to a finished cart...