Sending post xml-http request (AJAX) Using Dojo

function requestServer ()
{
        var query = "field=vale&field1=val1&..."
        var request = {};
        request['url'] = "server url ";
        request['handleAs'] = "xml";   // can be json,text,html
        request['load'] = showResult;  // which function to call on getting response from server
        request['error'] = showError;  // for any error which function to call
        request['postData'] = query;   // Send query to server
        dojo.rawXhrPost(request);   // Actuall call the XML-HTTP request
}

function showResult (response)
{
    alert(response)
}

function showError(response)
{
        alert("Error : " + response);
}