ajax同步模式的浏览器兼容有关问题

ajax同步模式的浏览器兼容问题
upload.php
PHP code

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
</head>

<body>
<form action="upload_deal.php" method="post"  name="form1" enctype="multipart/form-data" onsubmit="return upload();" >
<select name="hour" id="hour" >
  <option value="0" selected="selected">请选择</option>
  <option value="1">哈哈</option>
</select>
<input name="image" type="file" id="image" />
<input name="submit" type="submit" value="上传" />
</form>
<div id="status">f</div>
<script>
    function GetXmlHttpObject()
    {
        var XMLHttp=null;
        try
        {
            XMLHttp=new XMLHttpRequest();
        }
        catch(e)
        {
            try
            {
                XMLHttp=new ActiveXObject("Msxml2.XMLHTTP");
            }
            catch(e)
            {
                XMLHttp=new ActiveXObject("Microsoft.XMLHTTP");
            }
        }
        return XMLHttp;
    }
    
    function upload()
    {    
        var flag=false;
        var XMLHttp=GetXmlHttpObject();
        var url="upload_deal.php";
        var dataStr="hour="+document.getElementById("hour").value;
        XMLHttp.open("POST",url,false);
        XMLHttp.setRequestHeader("content-type","application/x-www-form-urlencoded");
        XMLHttp.send(dataStr);
        var resTest=XMLHttp.responseText;
        resTest=resTest.trim(); 
        var response_compent="true";
        if(resTest!=response_compent)
        {
            document.getElementById("status").innerHTML=resTest;
        }
        else
            flag=true;
        
        return flag;
    }
</script>
</body>
</html>




后台upload_deal.php
PHP code

    if($_REQUEST['hour']==1)
    {    
        echo "true";
    }
    else
    {
        echo "false";
    }



想实现将hour提交到后台判断,再根据返回值,true正确则提交表单、跳转,false错误则不提交表单、不跳转、给出提示。但是这个代码在firefox和谷歌等非ie内核的浏览器没有问题,但是使用ie(我这是9)就全部都跳转了。尝试加上回调函数的状态判断onreadystatechange,但是所有浏览器就都不执行了,一过onreadystatechange就直接到最后的return了。
PHP code

        XMLHttp.onreadystatechange=function()
        {
            if(XMLHttp.readyState==4&&XMLHttp.status==200)
            {
                var resTest=XMLHttp.responseText;
                resTest=resTest.trim(); 
                var response_compent="true";
                if(resTest!=response_compent)
                {
                    document.getElementById("status").innerHTML=resTest;
                }
                else
                    flag=true;
                
            }
        }



------解决方案--------------------
搜了搜,javascript没有trim()方法吧? resTest=resTest.trim();
------解决方案--------------------
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引用:

搜了搜,javascript没有trim()方法吧? resTest=resTest.trim();

这个还真有,不是这的问题