Ok, I wanna know if its even possable to when people enter my site it otomaticly sets the reslotion to the one I chose.

I tested my site on all resoltion and it only looks good on one certen resoltion

You can't do that, because that's attempting to adjust a person's personal computer settings.

All you could do would be make it open in a new js window to the resolution you want...but of course if its bigger than the persons actual resolution they arent going to be able to get around!
http://www.lissaexplains.com/javascript4.shtml#window