WebPlus X6: Webpage question

Hi, Can someone please tell me what code I would put in to make my website always viewable without the user having to scroll back and forth. I think it's with 100% in the code which always fills whatever window it's in... Hope I'm making sense.

Also, my site looks big in the preview....but smaller in Internet Explorer... what is the best size for a web page on the internet today with all the big screens and then the smaller laptop screens.

Thanks,
Leah