AJAX SIMPLE EXAMPLE

function XYZ() /////call this function
{
url = "Dog" //Servlet Name
if(window.XMLHttpRequest)//non IE
{
req = new XMLHttpRequest();
try
{
req.open("GET",url,true);
req.onreadystatechange=all_list_show;
}
catch(e)
{
alert("cannot connect to server");
}
req.send(null);
}
else if(window.ActiveXObject)//IE
{
try
{ req=new ActiveXObject("Msxml2.XMLHTTP");
}
catch(e)
{ req=new ActiveXObject("Microsoft.XMLHTTP");
}
if(req)
{ req.open("GET",url,true);
req.onreadystatechange=all_list_show;
req.send(null);
}
}
}
function XYZOUT()
{ if(req.readyState==4)
{ if(req.status==200)
{
document.getElementById('div_id').innerHTML=req.responseText;
}
}
}