function new_window(url) {
	var width = 1024;
	var height = 768;
	var left = (screen.availWidth - width) / 2;
	var top = (screen.availHeight - height) / 2;
	properties = 'top='+top+', left='+left+', width='+width+', height='+height+', resizable=1, scrollbars=1, menubar=1, toolbar=1, location=1, directories=1'
	window.open(url, properties)
}