js向php发送post请求失败，求解,该怎么处理

function alertWin(title, msg, w, h) { 
        var titleheight = "22px"; // 窗口标题高度 
        var bordercolor = "#666699"; //窗口的边框颜色 
        var titlecolor = "#FFFFFF"; // 窗口的标题颜色 
        var titlebgcolor = "#666699"; // 窗口的标题背景色 
        var bgcolor = "#FFFFFF"; // 内容背景色 
        var iWidth = document.documentElement.clientWidth; //这个窗口的宽度 
        var iHeight = document.documentElement.clientHeight; //这个窗口的高度 
        //创建一个弹出层 
        var msgObj = document.createElement("div"); 
        //设置弹出的层的样式 
        msgObj.style.cssText = "position:absolute;font:11px '宋体';top:" + (iHeight - h) / 2 + "px;left:" + (iWidth - w) / 2 + "px;width:" + w + "px;height:" + h + "px;text-align:center;border:1px solid " + bordercolor + ";background-color:" + bgcolor + ";padding:1px;line-height:22px;z-index:1001;"; 
        document.body.appendChild(msgObj); 
        //创建一个table用于容纳层上的内容 
        var table = document.createElement("table"); 
        //将Table放到弹出层上 
        msgObj.appendChild(table); 
        //设置table的格式 
        table.style.cssText = "margin:0px;border:0px;padding:0px;"; 
        table.cellSpacing = 0; 
        //插入一行用于显示标题 
        var tr = table.insertRow(-1); 
        //插入一个单元格用于容纳标题 
        var titleBar = tr.insertCell(-1); 
        titleBar.style.cssText = "width:100%;height:" + titleheight + "px;text-align:left;padding:3px;margin:0px;font:bold 13px '宋体';color:" + titlecolor + ";border:1px solid " + bordercolor + ";cursor:move;background-color:" + titlebgcolor; 
        titleBar.style.paddingLeft = "10px"; 
        //设置标题 
        titleBar.innerHTML = title; 
        //关闭按钮事件 
        var closeBtn = tr.insertCell(-1); 
        closeBtn.style.cssText = "cursor:pointer; text-align:right;padding:2px;background-color:" + titlebgcolor; 
        closeBtn.innerHTML = "×"; 
        closeBtn.onclick = function() { 
            document.body.removeChild(msgObj); 
        } 
        //弹出的消息窗口内容 
        var msgBox = table.insertRow(-1).insertCell(-1); 
        msgBox.style.cssText = "font:10pt '宋体';"; 
        msgBox.colSpan = 2; 
        msgBox.innerHTML = msg; 
        var nameBox1 = table.insertRow(-1); 
        var nameLable1 = nameBox1.insertCell(-1); 
        nameLable1.style.cssText = "font:10pt '宋体';text-align:center;"; 
        nameLable1.innerHTML = "手机 * "; 
		
		var nameBox2 = table.insertRow(-1); 
        var nameLable2 = nameBox2.insertCell(-1); 
        nameLable2.style.cssText = "font:10pt '宋体';text-align:center;"; 
        nameLable2.innerHTML = "验证码"; 
        
		var nameBox3 = table.insertRow(-1); 
        var nameLable3 = nameBox3.insertCell(-1); 
        nameLable3.style.cssText = "font:10pt '宋体';text-align:center;"; 
        nameLable3.innerHTML = ""; 
	}

	function get_mobile_code(){
		alert("111");
		$.post('http://'+serverIp+'smsExecute.php', {mobile:jQuery.trim($('#mobile').val()),send_code:}, function(msg) {
            alert(jQuery.trim(unescape(msg)));
        });
        alert("222");
	}