function systemAddEvent(object, event, fn, option)
{
	if (object.addEventListener)
	{
		object.addEventListener(event, fn, option);
	}
	else
	{
		object.attachEvent('on' + event, fn);
	}
}

function systemAddLoadEvent(func) {
  	var oldonload = window.onload;
  	if (typeof window.onload != 'function') {
    	window.onload = func;
  	} else {
    	window.onload = function() {
	      	if (oldonload) {
	        	oldonload();
	      	}
	      	func();
    	}
  	}
}

function systemIsIE() {
	if (navigator.appName == "Microsoft Internet Explorer") {
		return true;
	} else {
		return false;
	}
}

function systemIsChrome() {
	if (!systemIsIE()) {
		if (navigator.vendor.indexOf("Google") != -1) {
			return true;
		} else {
			return false;
		}
	}
	return false;
}