var navigatorname;
if (navigator.userAgent.indexOf("Opera")>=0){
	navigatorname="Opera"
}
if (navigator.userAgent.indexOf("MSIE")>=0) { 
	navigatorname="IE"
}
if (navigator.userAgent.indexOf("Firefox")>=0){ 
	navigatorname="Firefox"
}


//获得Id对象
function $(id) {
	return document.getElementById(id);
}
//获取ID对象
function $id(id,obj){
	if(obj==null){return document.getElementById(id)}
	else{return obj.getElementById(id)}
}

//AJAX 对象
var GetHttpRequest=function() {
	var request = false;
	if(window.XMLHttpRequest) {
		request = new XMLHttpRequest();
		if(request.overrideMimeType) {
			request.overrideMimeType('text/xml');
		}
	} else if(window.ActiveXObject) {
		var versions = ['Microsoft.XMLHTTP', 'MSXML.XMLHTTP', 'Microsoft.XMLHTTP', 'Msxml2.XMLHTTP.7.0', 'Msxml2.XMLHTTP.6.0', 'Msxml2.XMLHTTP.5.0', 'Msxml2.XMLHTTP.4.0', 'MSXML2.XMLHTTP.3.0', 'MSXML2.XMLHTTP'];
		for(var i=0; i<versions.length; i++) {
			try {
				request = new ActiveXObject(versions[i]);
				if(request) {
					return request;
				}
			} catch(e) {}
		}
	}
	return request;
}

//用于获取相应地址返回的Json对象
function GetJsonObj(urlstr){
	try{
		var http_request=GetHttpRequest();
		urlstr.indexOf("?")==-1?urlstr=urlstr+"?"+Math.random():urlstr=urlstr+"&"+Math.random();
		http_request.open("GET",urlstr,false);
		http_request.send(null);
		var tStr=http_request.responseText;
		return eval("("+tStr+")");
	}catch(e){
		//prompt("错误页面地址:",urlstr);
		//alert("加载数据错误:\n"+tStr+e.toString);
		alert("加载数据错误:\n"+e.toString);
		return null;
	}
}


String.prototype.trim=function(){
　　 return this.replace(/(^\s*)|(\s*$)/g, "");
}

String.prototype.ltrim=function(){
　　 return this.replace(/(^\s*)/g,"");
}

String.prototype.rtrim=function(){
　　 return this.replace(/(\s*$)/g,"");
}