ajax for beginners

I dont know why some one has named it ajax. but in 2003 i have written an application using xmlhttp object . which was used to communicate with xml webservice to get a resultset. and display the results in excel.

i will show the example what i have done in my next post.

motivation is share mere yaar " share the knowledge" .

ajax is asynchronous call made using javascript either to the .net web application or webservice.

we need following minumum javascript methods to make a call.

/*---- Get xml http object ---*/

function GetXmlHttpObject() {
var xmlHttp = null;
try {
// Firefox, Opera 8.0+, Safari
xmlHttp = new XMLHttpRequest();
}
catch (e) {
// Internet Explorer
try {
xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
}
catch (e) {
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
}
return xmlHttp;
}

/*---------------------*/



function stateChanged() {
if (xmlHttp.readyState == 4) {
....Write your code to assign response to the html dom element.
}
}


here is the java script funtino can be called on each key up on text box
following function gets the employee details from getEmployee.aspx page.

function showEmployee(str) {
xmlHttp = GetXmlHttpObject();
if (xmlHttp == null) {
alert("Your browser does not support AJAX!");
return;
}
var url = "getEmployee.aspx";
url = url + "?q=" + str;
url = url + "&sid=" + Math.random();
xmlHttp.onreadystatechange = stateChanged;
xmlHttp.open("GET", url, true);
xmlHttp.send(null);
}

any questions please drop a question.

thanks