if(document.all) { 
    var obj = new ActiveXObject("Microsoft.XMLHTTP"); 
}else{ 
    var obj = new XMLHttpRequest(); 
} 
function refreshData(loc, data) { 
    var content = document.getElementById(loc); 
    obj.open("POST", 'process_request.php'); 
    obj.onreadystatechange = function() { 
        if (obj.readyState == 4 && obj.status == 200) 
            content.innerHTML = obj.responseText; 
    } 
    obj.setRequestHeader('Content-Type','application/x-www-form-urlencoded'); 
    obj.send(data); 
}