//定义StringBuffer对象开始
function StringBuffer(){
	this.data=[];
} 
StringBuffer.prototype.append=function(){
	this.data.push(arguments[0]);
	return this;
} 
StringBuffer.prototype.tostring=function(){
	return this.data.join("");
} 
//StringBuffer对象结束

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

function $(id)
{
   return document.getElementById(id);
}
//S

//获得元素的位置
function getposition(element,offset){
    var c=0;
    while(element){
        c+=element[offset];
        element=element.offsetParent
    }
    return c;
}
//获得元素的位置
function getLeft(element)
{
    var c=0;
    while(element)
    {
        c+=element['offsetLeft'];
        element=element.offsetParent
    }
    return c;
}

/** 
* XMLHttpRequest Object Pool 
*/ 
var XMLHttp = { 
	_objPool: [], 
	_getInstance: function () 
	{ 
		for (var i = 0; i < this._objPool.length; i ++) 
		{ 
			if (this._objPool[i].readyState == 0 || this._objPool[i].readyState == 4) 
			{ 
			return this._objPool[i]; 
			} 
		} 

		// IE5中不支持push方法 
		this._objPool[this._objPool.length] = this._createObj(); 
		return this._objPool[this._objPool.length - 1]; 
	}, 
	_createObj: function () 
	{ 
		if (window.XMLHttpRequest) 
		{ 
			var objXMLHttp = new XMLHttpRequest(); 
		} 
		else 
		{ 
			var MSXML = ['MSXML2.XMLHTTP.5.0', 'MSXML2.XMLHTTP.4.0', 'MSXML2.XMLHTTP.3.0', 'MSXML2.XMLHTTP', 'Microsoft.XMLHTTP']; 
			for(var n = 0; n < MSXML.length; n ++) 
			{ 
				try 
				{ 
					var objXMLHttp = new ActiveXObject(MSXML[n]); 
					break; 
				} 
				catch(e) 
				{ 
				} 
			} 
		} 

		// mozilla某些版本没有readyState属性 
		if (objXMLHttp.readyState == null) 
		{ 
			objXMLHttp.readyState = 0; 
			objXMLHttp.addEventListener("load", function (){ 
														  objXMLHttp.readyState = 4; 
														  if (typeof objXMLHttp.onreadystatechange == "function")
														  { 
														  	objXMLHttp.onreadystatechange(); 
															} 
														}, false);
		}
		return objXMLHttp; 
	}, 

	// 发送请求(方法[post,get], 地址, 数据, 回调函数) 
	sendReq: function (method, url, data, callback) 
	{ 
		var objXMLHttp = this._getInstance(); 
		with(objXMLHttp) 
		{ 
			try 
			{ 
				// 加随机数防止缓存 
				if (url.indexOf("?") > 0) 
				{ 
					url += "&randnum=" + Math.random(); 
				} 
				else 
				{ 
					url += "?randnum=" + Math.random(); 
				} 
				open(method, url, true); 
				
				// 设定请求编码方式 
				setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8'); 
				send(data); 
				onreadystatechange = function () 
				{ 
					if (objXMLHttp.readyState == 4 && (objXMLHttp.status == 200 || objXMLHttp.status == 304)) 
					{ 
					callback(objXMLHttp); 
					} 
				} 
			} 
			catch(e) 
			{ 
				alert(e); 
			} 
		} 
	} 
};