Firstly
Welcome to WT.. Enjoy ur stay here
secondly to ur q,
design ur site using % values then you will not have to worry abt which screen resolution ur visitor comes in..
after technology improvements, atlease 60-70% ppl use 1024x768..
but again this depends on which continent/country or rather who are ur target audience.
if ur audience is going to be one from say,india,srilanka, pakistan, etc.
then mostly 800*600 is used.
again if u target usa,europe,aus.. then 1024 should not do anyharm..
but
BEFORE U DO ANYTHING. CHECK UR SITE IN BOTH RESOLUTIONS.. SO THAT U GET WHAT U DESIGNED FOR..
ok..
expand page design??
u can use js to detect the resolution and redirect them to the appropriate pages.. but again that is double trouble. u have to do the pages twice. one for 1 resolution and 1 for other resolutions..
it is best if u keep ur table widths to PERCENTAGE values. so that they will expand and contract with the resolution..
let me know if this helps.
for ref.. u can take my site..
i have desinged using 1024.. but it is the same in 800..
have a look at it.
and if u need further help let know
enjoy ur stuff and have a nice time..