function open_win( url, ww, wh, wname ) {

	var sw = screen.width;
	var sh = screen.height;
	var swc = (sw-ww)/2;
	var shc = (sh-wh)/2;
	
	window.open(url,wname,"left="+swc+",top="+shc+",resizable=1,scrollbars=yes,status=no,width="+ww+",height="+wh+";" );
}

function isEmail(string) {
	if (string.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1)
		return true;
	else
		return false;
}