Question

There appear to be two issues with the original question:
1) The sleep function didnt properly simulate a long running operation such as an HTML request.
2) IE, at least v8 and v9 dont appear to update their display correctly the way Firefox does. Anyone know a way to force IE to process the UI update?
The following works fine on Firefox but IE Doesnt update the display of the running count until the end unless I insert an alert which forces a pause. If there are 50 items and the batch size is 10, I wanted the HTML displaying the running count to show 10,20,30,40,50. In IE it jumps from 10 to 50 at the end whereas Firefox updates correctly.

while (done == false) {
    var url = 'myLongRunningOperation.com/doSomething.html&LastID='+lastPriorIndex;
    $.ajax({
    type: 'GET',
    url: url,
    dataType: 'json',
    success: function(data) { 
        soFar += data.Succeeded + data.Failed;
        $('#numCompleted').val(soFar).show();
        LastPriorIndex= data.LastID;
        if (soFar >= totalNumberOFDocs) {
        done = true;
        }
    },
    data: {},
    async: false
    });
}

I’m trying to use a JQuery UI modal dialog as a status dialog. First it should display, then process the update messages as a long running operation completes and adds to the HTML. However, the dialog doesnt display till the very end and then shows up with all of the messages. If I put in an alert just after showing the dialog, it will show but the message updates all show up at once after the operations are all done. I’m hoping all I need is some sort of check-the-message-queue function to get it to update because the alert causes the dialog to show. Or possibly it’s my method of simulating a log running operation that’s the problem in simulating a sleep.

    $(function() {
        $("#dialog2").dialog({
            bgiframe: false
            ,height: 140
            ,modal: true
            ,autoOpen: false
        });

    });
    function TestModalUpdate2() {
        $('#dialog2').dialog("open");
        //alert('foo'); //if this alert is present the dialog shows before the doSomething calls execute but wont update till all of them are done
        $('#dialog2').show();
        var i
        for(i = 0; i < 5; i++) {
            doSomething($('#dialog2'));
            $('#dialog2').show();
        }
    }

    function doSomething(obj1) {
        wait(1000);
        obj1.html(obj1.html()+"<p>new line</p>")
                //alert('this will also cause the dialog to update in between doSomethings')
    }
    function wait(msecs) {
        var start = new Date().getTime();
        var cur = start
        while(cur - start < msecs) {
            cur = new Date().getTime();
        }
    } 
<input type="button" id="Test2" onclick="TestModalUpdate2();" value="Test2"/>

Answer 1

After further research indicating that operating in synchronous mode can be troublesome, I converted it to a recursive version which worked.

function processBatch() {
    var url = 'DoSomethingLongRunning.html&StartingIndex='+startingIndex+'&BatchSize='+batchSize;
    $.getJSON(url 
        ,function(data) { 
            soFar1 += data.Succeeded + data.Failed;
            $('#numCompleted').val(soFar1).show();
            startingIndex = data.LastID;
            if (soFar1 < totalNumberOfDocs) {
                processBatch();
            }
        }
    );  
}