// 元素事件操作
eventListeners = []
function findEventListener(node, event, handler){
	var i;
	for (i in eventListeners){
		if (eventListeners[i].node == node && eventListeners[i].event == event && eventListeners[i].handler == handler){
			return i;
		}
	}
	return null;
}
function myAddEventListener(node, event, handler){
	if (findEventListener(node, event, handler) != null){
		return;
	}
	if (!node.addEventListener){
		node.attachEvent('on' + event, handler);
	}else{
		node.addEventListener(event, handler, false);
	}
	eventListeners.push({node: node, event: event, handler: handler});
}

// 判断浏览器
function brower() {
	var ua = LCase(navigator.userAgent);
	var os = new Object();
	os.isFirefox = ua.indexOf ('gecko') != -1;
	os.isOpera = ua.indexOf ('opera') != -1;
	os.isIE = !os.isOpera && ua.indexOf ('msie') != -1;
	os.isIE7 = os.isIE && ua.indexOf ('7.0') != -1;
	return os;
}
// 返回字符串的小写
function LCase(Str) {
	if(Str == null) return;
	return Str.toLowerCase();
}
//打开窗口
function showDialog(url) {
	var width=980;
	var height= 650;
	if(brower().isIE7){
		height= 650;
	}else{
		height= 675;
	}
	var dialogWin = null;
	var left = (window.screen.width-width)*0.5>>0;
	var top = (window.screen.height-height-30)*0.5-30>>0;
	if(brower().isIE) {
		dialogWin = window.showModalDialog(url,window, 'dialogWidth:'+width+'px;dialogHeight:'+height+'px;dialogLeft:'+left+'px;dialogTop:'+top+'px;edge:sunken;center:1;scroll:0;help:0;resizable:0;status:0;location:0;');
	}else{
		dialogWin = window.open(url, "", "width="+width+"px,height="+height+",left="+left+",top="+top);
		
		function addFocus() {
			if(dialogWin.closed == false){
				dialogWin.focus();
			}
		}
		myAddEventListener(window, 'focus', addFocus);
	}
	return dialogWin;
}