function dcheck() {
	
	var myWidth = 0, myHeight = 0;
	if( typeof( window.innerWidth ) == 'number' ) {
//Non-IE
		myWidth = window.innerWidth;
		myHeight = window.innerHeight;
	} else if( document.documentElement && ( document.documentElement.clientWidth || document.documentElement.clientHeight ) ) {
//IE 6+ in 'standards compliant mode'
		myWidth = document.documentElement.clientWidth;
		myHeight = document.documentElement.clientHeight;
	} else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
//IE 4 compatible
		myWidth = document.body.clientWidth;
		myHeight = document.body.clientHeight;
	}

	if ((myHeight != 0) && ( myHeight < 500 )) {
		document.getElementById("bottomlogo").style.display = "none";
	} else {
		if ( myHeight > 510 ) {
			document.getElementById("bottomlogo").style.display = "block";
		}
	}
}