function ajaxFunction()
{
    var xmlHttp;
    try
    {  // Firefox, Opera 8.0+, Safari  
        xmlHttp=new XMLHttpRequest(); 
    }
    catch (e)
    {  // Internet Explorer  
        try
        {    
            xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");   
        }
        catch (e)
        {    
            try
            {     
                xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");     
            }
            catch (e)
            {     
                alert("Your browser does not support AJAX!");      
                return false;      
            }    
        }  
    } 
    
    return xmlHttp; 
}