// height fix
function fixHeight () {
	if (document.getElementById) {
		if (window.innerHeight) {
			var availHeight = window.innerHeight;
		} else if (document.all) {
			if (document.body.clientHeight) {
				var availHeight=document.body.clientHeight;
			} else {
				var availHeight=document.documentElement.clientHeight;
			}
		}
		if (typeof(availHeight)!='undefined') {
			var newHeight = (availHeight - 550)/2
			if (newHeight <= 0) {
				newHeight = 0;
			}
			document.getElementById('push').style.height = newHeight + 'px';
		}
	}
}
fixHeight();
window.onresize=fixHeight;