Internet Explorer错误消息“操作已超时”

Question

I have a piece of code that works in chrome and firefox but not in internet explorer. I can't figure out what that actual cause is. I get a operation timeout message from internet explorer "Message: The operation was timed out."

This is the ajax function I am using, it's from w3schools so I know this is correct.

function ajax() {    
    var xmlhttp;
    if (window.XMLHttpRequest)
    {// code for IE7+, Firefox, Chrome, Opera, Safari
        xmlhttp=new XMLHttpRequest();
    }
    else
    {// code for IE6, IE5
        xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
    }

    alert(xmlhttp);
    return xmlhttp;
}

This is the code that's getting stuck on. The error message is in "ajaxRequest.send(postdata);" .

function edit(){
    var ajaxRequest = ajax();   
    var postdata = "data=" + document.getElementById("id1").value + "<|>" + document.getElementById("id2").value + "<|>" +  document.getElementById("id3").value;


    ajaxRequest.onreadystatechange = function(){
            var ajaxDisplay = document.getElementById('ajaxDiv');
        if(ajaxRequest.readyState == 4 && ajaxRequest.status==200){
            ajaxDisplay.innerHTML = ajaxRequest.responseText;
        }
    }   
    alert(postdata);
    ajaxRequest.open("POST","confirmPage.php",false);
    ajaxRequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    ajaxRequest.send(postdata);
    alert("Finished");
}

All the other pages work with the same code in internet explorer but not this particular page. I can't seem to figure to out why. This page works in chrome and firefox but not in internet explorer. It never goes to "Finished". I am using IE 8.

Answer 1

As you require synchronous behaviour try the following:

ajaxRequest.open("POST", "confirmPage.php", false);
ajaxRequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
ajaxRequest.send(postdata);

if (ajaxRequest.status === 200) {
    document.getElementById('ajaxDiv').innerHTML = ajaxRequest.responseText;
}

alert("Finished");

You don't need the onreadystatechange as the request is synchronous.

Answer 2

Partial answer:

I figured out the problem. It's not javascript and/or ajax. IE can't handle a large number of results in queries so it times out. It's a very obscure error as I was thinking it's something to do with the ajax functions rather than the php file.

The result set is not huge. There are 5 different queries. Each one with about 5-50K records(I am not printing all of them, just querying). It times out after a large result set.

To test I created a test page with simple SELECT * queries and it can handle only 2-3 queries. If it's more than that it times out.