function setTopMargin() {
	myHeight = 0;
	if( typeof( window.innerHeight ) == 'number' ) {
		//Non-IE
		myHeight = window.innerHeight;
	}
	else if( document.documentElement && ( document.documentElement.clientHeight ) ) {
		//IE 6+ in 'standards compliant mode'
		myHeight = document.documentElement.clientHeight;
	}
	else if( document.body && ( document.body.clientHeight ) ) {
		//IE 4 compatible
		myHeight = document.body.clientHeight;
	}
	topmargin = Math.round( ( myHeight - 600 )/2 );
	//window.alert( topmargin );
	document.getElementById('wrapper').style.marginTop=topmargin+'px';
	//document.getElementsByTagName('body').style.marginTop=topmargin;
}

//window.onload = setTopMargin;
//window.onresize = setTopMargin;