window.onload = function() {
	// png fix (IE 5.5 e 6)
	if (document.all && document.styleSheets && document.styleSheets[0] && document.styleSheets[0].addRule) {
		document.styleSheets[0].addRule('img', 'behavior: url("../includes/iepngfix.htc")');
	}
	
	if ($.ajax)
		setInterval(function() { new $.ajax('../_sessionHelper.php'); }, 180000);
	else
		setInterval(function() { new Ajax.Request('../_sessionHelper.php'); }, 180000);
}