使用AJAX时页面卡住

I'm using AJAX to present calculation results. I invoke a PHP file that returns the results, and then I present it on the web page.

Sometimes the calculation takes a long time, and the page gets stuck until the AJAX call has returns the results.

Is there a way to use ajax, and still get the ability to perform other actions on the web page, and don't have to wait until the AJAX call has returned.

I'm using this AJAX call function( a standard function as i know).

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

    xmlhttp.onreadystatechange = function()
    {
        if (xmlhttp.readyState==4 && xmlhttp.status==200)
        {        
            result = xmlhttp.responseText ;             
        }
    }

    xmlhttp.open("GET","GetRouts.php?q="+str,false);
    xmlhttp.send();
    result = xmlhttp.responseText ;
    return result;
}

Ajax is async if you need your javascript to work with the data send by the request you need to wait for the callback. If you dont need to work with the data from the request ( for example animate something etc...) you can just write your code outside of this function.

Yes, just pass true as the third parameter to open, then process the result in the onreadystatechange event instead.