function addLoadEvent(_function) {
	var _onload = window.onload;
	if (typeof window.onload != 'function') {
		if (window.onload) {
			window.onload = _function;
		} else {
			var _addEventListener = window.addEventListener || document.addEventListener;
			var _attachEvent = window.attachEvent || document.attachEvent;
			if (_addEventListener) {
				_addEventListener('load', _function, true);
				return true;
			} else if (_attachEvent) {
				var _result = _attachEvent('onload', _function);
				return _result;
			} else {
				//todo: preloading fix for ie5.2 on mac os
				return false;
			}
		}
	} else {
		window.onload = function() {
			_onload();
			_function();
		}
	}
}