Java Ajax Initialization

<script type= "Text/javascript" >
var http_request = false;
function Createxmlhttprequest () {
if (window. ActiveXObject) {//IE browser
Http_request = new ActiveXObject ("Msxml2.xmlhttp"); Create a XMLHttpRequest Object
}else if (window. XMLHttpRequest) {//Non IE browser
Http_request = new XMLHttpRequest (); Create a XMLHttpRequest Object
}
if (!http_request) {
Alert ("Cannot create XMLHttpRequest object instance! ");
return false;
}
}
function GetResult () {
var ResponseContext; Used to store response results returned from the server
if (http_request.readystate = = 4) {//Determine request status
if (Http_request.status = = 200) {//request succeeded, start processing return result
ResponseContext = Http_request.responsetext; Get the response content of the server
if (Responsecontext.indexof ("true")!=-1) {
Alert ("Congratulations! The user name is valid! ");
}else{
Alert ("Sorry! The user name has already been registered! ");
}
} else {//request page has errors
Alert ("The page you requested has an error! ");
}
}
}

function Checkusername (username) {
if (Username.value = = "") {
Alert ("Please enter your username!") ");
Username.focus ();
Return
} else {
Createxmlhttprequest ();
Http_request.onreadystatechange = GetResult; Call return result handler function
Http_request.open ("GET", "Checkuser?username=" +username.value, true); Create a connection to the server
Http_request.send (NULL); Send a request to the server
}
}
</script>

Example 2:

<script type= "Text/javascript" >var xmlHttp=false; function Createxmlhttprequest () {if(window. ActiveXObject) {xmlHttp=NewActiveXObject ("msxml2.xmlhttp.3.0"); }Else if(window. XMLHttpRequest) {xmlHttp=NewXMLHttpRequest ();            }} function Startrequest () {createxmlhttprequest (); Xmlhttp.onreadystatechange=Handlestatechange; Xmlhttp.open ("GET", "Http://localhost:8080/MyFirstWebPro/user.xml",false);        Xmlhttp.send (); } function Handlestatechange () {if(Xmlhttp.readystate = = 4){                if(Xmlhttp.status = = 200) {document.getElementById ("Results"). InnerHTML =Xmlhttp.responsetext; }Else{alert ("The page you requested has an error!" "); }            }        }    </script>

<body onload= "Startrequest (); >
<div id= "Results" ></div>

User.xml as follows

<?XML version= "1.0" encoding= "gb2312"?><Table>    <TR>        <th>Name</th>        <th>Age</th>        <th>Gender</th>    </TR>    <TR>        <TD>Wang Lili</TD>        <TD>22</TD>        <TD>Woman</TD>    </TR>    <TR>        <TD>Zhang Fang</TD>        <TD>22</TD>        <TD>Woman</TD>    </TR>    <TR>        <TD>Zhang Hui</TD>        <TD>22</TD>        <TD>Man</TD>    </TR></Table>

Java Ajax Initialization