javascript executing before form submission

Question

I have a simple html form which takes in the username and password and registers it in a database. However it executes the following php if statement once as soon as the page loads even before the form is submitted. The following is that piece of code.

if (($_POST['reg_username']=="") || ($_POST['reg_password']==""))
{ ?>
<script> alert("please enter both email and password"); </script>

<? }

The full php code is down below. This is not the final code so I still did not encrypt the passwords and everything but I am just testing it out. Thanks in advance guys.

if (($_POST['reg_username']=="") || ($_POST['reg_password']==""))
{ ?>
<script> alert("please enter both email and password"); </script>

<? }


$reg_username=mysql_real_escape_string($_POST['reg_username']);
$reg_username=htmlspecialchars($reg_username);
$reg_password=mysql_real_escape_string($_POST['reg_password']);
$reg_password=htmlspecialchars($reg_password);



if(!empty($reg_username) && !empty($reg_password))
{

if (isset($reg_username) && isset($reg_password))
{
mysql_select_db($db, $dbconnect);
mysql_query("INSERT into students(username,password) VALUES    
('$reg_username','$reg_password')");
}
}

?>

possible duplicate of [Reference: Why does the PHP (or other server side) code in my Javascript not work?](http://stackoverflow.com/questions/13840429/reference-why-does-the-php-or-other-server-side-code-in-my-javascript-not-wor) — Quentin, Jan 30 '14 at 17:26

score 0 · Answer 1 · answered Jan 30 '14 at 17:30

Why you have to include those tags inside PHP? Why you just don't do it separately. Here's an example with Javascript (jQuery):

Note that there might be some typos and syntax errros since I wrote that snippet within minute.

<script type="text/javascript">

$(document).ready(function() {

("#login_form").submit(function() {

var username = ("#selector").val();
var password = ("#password").val();

if(username == "" && password == "") {

alert("please enter both email and password");

}
}

)};
</script>

score 0 · Accepted Answer · answered Jan 30 '14 at 17:31

0

Change this:

if (($_POST['reg_username']=="") || ($_POST['reg_password']==""))
{ ?>
<script> alert("please enter both email and password"); </script>

<? }

Into this:

if(isset($_POST['reg_username']) || isset($_POST['reg_password'])) 
{
if (($_POST['reg_username']=="") || ($_POST['reg_password']==""))
{ ?>
<script> alert("please enter both email and password"); </script>

<?php }
}

answered Jan 30 '14 at 17:31

Hackerman

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Thanks Robert, It is working now. Also when I created a new php file with my initial code and redirected the form values to that file, it worked too. Thanks once again. – user3150373 Jan 30 '14 at 17:36
I'm glad to help, feel free to mark this answer as correct ;) – Hackerman Jan 30 '14 at 17:41

score 0 · Answer 3 · answered Jan 30 '14 at 17:33

 if(isset($_POST['SubmitButtonName'])){ //check if form was submitted
      unset($_POST['SubmitButtonName']);
      if (($_POST['reg_username']=="") || ($_POST['reg_password']==""))
      { ?>
           <script> alert("please enter both email and password"); </script>
      <? }
 }

Remember to change SubmitButtonName

score 0 · Answer 4 · answered Jan 30 '14 at 17:46

      <script>
     $(document).ready(function(){
     $("#submit").click(function(){
    var register_name=$('#reg_username').val();
var register_password=$('#reg_password').val();

if(register_name =="")
{
alert("please enter your name");
return false;
} else if(register_password =="")
{
alert("please enter your password");
return false;
}
else
{
return true;
}
        });
       });
           </script>
        </head>
        <body>
          <form action="" method="post">
          Register name:<input type="text" name="reg_username" id="reg_username"><br>
       Password: <input type="password" name="reg_password" id="reg_password"><br>

            <input type="submit" id="submit">
         </form>
    </html>

please use Jquery validation instead of using php for this purpose because of php is server side and jquery is client side — Vivek Kumar, Jan 30 '14 at 17:47

javascript executing before form submission

4 Answers4