<script language="JavaScript">
<!--
var correctwidth=800;
var correctheight=600;
if (screen.width<=correctwidth||screen.height<=correctheight)
window.location="http://www.site1.co.il";
else if (screen.width>correctwidth||screen.height>correctheight)
window.location="http://www.site2.co.il";
//-->
</script>