ajax无刷新更新数据与无刷新提交代码

if( $_POST || $_GET )
{
 $cn = mysql教程_connect('localhost','root','123456a');
 $data = $_POST['data'];
 $sql = "update test set data='$data' where id=1";
 mysql_db_query('db',$sql,$cn);
}
?>

<form name="form1" method="post" action="">
  <label>
  <input name="datavalue" type="text" id="data">
  </label>
  <label>
  <input type="button" name="Submit" value="保存数据" onClick="javascript教程:ajaxSava();">
  </label>
  <div id="dv111cn"></div>
</form>

<script language="javascript">

var xmlhttp;

function ajaxSava(){
 var url = "ajaxsava.php教程";
 var oBao = CreateHTTPObject();
 var data = form1.datavalue.value;
 alert(data);
 oBao.open("POST",url,true);
 oBao.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
 oBao.onreadystatechange = function () { OnReadyStateChng();};
 oBao.send("data="+data);
}

function OnReadyStateChng() {
    if (xmlhttp.readyState == 4) {
        if (xmlhttp.status == 200) {
            document.getElementById.innerHTML = unescape(xmlhttp.responseText);
        }
        else {
   document.getElementById('dv111cn').innerHTML = "失败,<a href='javascript:;' onclick='checkRep(this);'>重新提交</a>";
        }
    }else{
  document.getElementById('dv111cn').innerHTML = "<img class=loading src='img/loading.gif'>";
 }
}

function CreateHTTPObject(){
  
   
    try {
        xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch (e) {
        try {
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
        catch (e) {
            xmlhttp = false;
        }
    }
   
    if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
        try {
            xmlhttp = new XMLHttpRequest();
        }
        catch (e) {
            xmlhttp=false;
        }
    }
   
    if (!xmlhttp && window.createRequest) {
        try {
            xmlhttp = window.createRequest();
        }
        catch (e) {
            xmlhttp=false;
        }
    }
   
    return xmlhttp;
}

</script>