Php+ajax when checking user name or mail registration there are instances tutorial _php tips

Php+ajax detection of user name or mail registration is already existing in the forum or membership system is a common important function. This paper describes the implementation method of this function in the form of an instance. The specific steps are as follows:

First, the PHP test page

The check.php page code is as follows:

<script type= "Text/javascript" src= "jiance.js" ></script> <form name= "MyForm" action= "method="
Get >
 username: <input name= "user" value= "type=" text "onblur=" funtest100 () "/> <div id="
 test100 "> </div>
</form>

Second, the AJAX verification page

The Check.js page code is as follows:

var xmlHttp;
function S_xmlhttprequest () {
  if (window). ActiveXObject) {
    xmlHttp = new ActiveXObject (' microsoft.xmlhttp ');
  } else if (window. XMLHttpRequest) {
    xmlHttp = new XMLHttpRequest ();
  }
}
function funtest100 () {
  var f = document.getelementsbytagname_r (' form ') [0].user.value;//gets text box content
  S_ XMLHttpRequest ();
  Xmlhttp.open ("Get", "jcfor.php?id=" +f,true);/Open Request
  Xmlhttp.onreadystatechange = byphp;//ready to execute
  Xmlhttp.send (null);//Send
}
function byphp () {
  //Judge status
  if (xmlhttp.readystate==1) {//ajax State
    document.getelementbyidx_x_x (' test100 '). InnerHTML = "Loading";
  }
  if (xmlhttp.readystate==4) {//ajax state
    if (xmlhttp.status==200) {//server-side State
      var bytest100 = Xmlhttp.responsetext;
      alert (bytest100);
      document.getelementbyidx_x_x (' test100 '). InnerHTML = bytest100;}}

Third, PHP verification page

The chkfor.php page code is as follows:

<?php
 if ($_get[id]) {sleep
    (1);
    $conn =mysql_connect (' localhost ', ' root ', ');
    mysql_select_db (' Test ', $conn);
    $sql = "SELECT * from ' user ' WHERE ' name ' = ' $_get[id] '";
    $q =mysql_query ($sql);
 
    if (Is_array (Mysql_fetch_row ($q)) {
      echo "user name already exists"; 
    } else{
      echo "User name can be used" 
    ;
 }  
? >

I hope the example described in this article will help you with PHP program development.