javascript - Check Username in Registration form -

in following code, want username checked if it's available or not before submiting form. used onchange() event username field.

html code:

<form method="post" action="regconf.php">     <p>         <input type="text" id="username" name="username" value="" placeholder="username" onchange="check_ava()">          <span id='ava_result'>     </p>     <p>         <input type="password" id="password" name="password" value="" placeholder="password">     </p>     <p>         <input type="password" id="confpassword" name="confpassword" value="" placeholder="confirm password" onchange="check()">          <span id='message'>     </p>     <p>         <input type="text" name="email" value="" placeholder="email">     </p>     <p>         <input type="text" name="phone" value="" placeholder="phone">     </p>     <p>         <input type="text" name="address" value="" placeholder="address">     </p>     <p class="submit">         <input type="submit" id="submit" name="commit" value="submit">         <button type="reset" value="reset">reset</button>     </p> </form> 

function check_ava() {       var username = document.getelementbyid('username').value;       $.post("check_username.php", { username: username }, function(result){            if (result == 1) {               document.getelementbyid('ava_result').innerhtml = "username available";             document.getelementbyid('submit').disabled = false;         } else {               document.getelementbyid('ava_result').innerhtml = "username not available";             document.getelementbyid('submit').disabled = true;         }       });   }  

<?php     include 'dbconnection.php';      $username = mysql_real_escape_string($_post['username']);       $result = mysql_query('select name user name = "'. $username .'"');       if (mysql_num_rows($result) > 0) {           echo 0;       } else {           echo 1;       } ?> 

the problem is not working , not checking username.

you have use remote method:

<script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.13.1/jquery.validate.min.js"></script>   <script>      $(function() {                 $('#form-validation').validate({                      rules: {                          username: {                             required: true,                             remote: {                             url: "check_username.php",                             type: "post"                      }                         },                      },                     messages: {                       val_number: 'please enter value!',                      }                 });               }); </script> 

and check_username.php is,

$registeredname[] = //select names in databse using select , store here array,   $requestedname  = $_post['username']; if(in_array($requestedname,$registeredname)) {     echo 'false'; } else {     echo 'true'; }