Page refreshes on submit click with ajax

I have a small commenting system that I have modified and try implement into the site. It's in 'ajax'. When the jQuery with HTML is embedded into the page the commenting system works fine - i.e. when the user clicks on a submit button the code returns 'false', stops the page from refreshing and submits data. BUT when I implemented the code within my site and placed it in a seperate .js file the code for some reason doesn't work properly. I mean - the page after the onclick refreshes. Why is that so ? The code is not changed at all - when on its own, it works but not in the index.php site when implemented. I tried to change input type to 'button' and call a function from onclick - the page doesn't refresh but also doesn't insert the input..I'm running out of ideas as to why it is that so. Here's the code:

$(document).ready(function () {
        $(".submit").click(function () {
            var name = $("#name").val();
            var email = $("#email").val();
            var comment_area = $("#comment_area").val();
            var dataString = 'name=' + name + '&email=' + email + '&comment_area=' + comment_area;
            var emailReg = /^([\w-\.]+@([\w-]+\.)+[\w-]{2,4})?$/;
            var emailaddressVal = $("#email").val();
            if (name == '' || !emailReg.test(emailaddressVal) || comment == '') {
                alert('Please enter valid data and type in message'); return false;
            }
            else {
                $.ajax({
                    type: "POST",
                    url: "comments.php",
                    data: dataString,
                    cache: false,
                    success: function (html) {
                        $("#com_list").append(html);
                        $("#com_list").fadeIn("slow");
                        $("#flash").fadeOut('fast');

                    }
                });
            } return false;
        });
    });
//END
//COM LIST

//HTML / PHP
<div class="slider">
<form id="comment_form" name="comment_form" method="post" action="#"     
enctype="multipart/form-data">
<input type="text" id="name" n开发者_如何学运维ame="name" maxlength="16"/>&nbsp;Name<br /><br/>
<input type="text" id="email" name="email"/>&nbsp;Email&nbsp;(will not show)<br /><br/>
<textarea id="comment_area" name="comment_area" maxlength="1000"></textarea><br /><br/>
<input type="submit" class="submit" name="submit_comment" value="submit"/>&nbsp;&  
nbsp;comment or <a href="index.php" id="cancel"   
onmousedown="$('.slider').hide();$('#com_list').show();"><u>cancel</u></a>
</form>
</div>

//comments.php

 if($_POST) {
 $name=$_POST['name'];
 $email=$_POST['email'];
 $comment_area=$_POST['comment_area'];
//$lowercase = strtolower($email);
//$image = md5( $lowercase );
$insert = mysqli_query($connect,"INSERT INTO comments (name,email,comment,com_date)   
VALUES ('$name','$email','$comment_area',curdate())"); 

}

////////////////

Thanks for any suggestions..

aha!

there is an error in your js:

in my console i'm getting "comment is not defined "

if(name=='' || !emailReg.test(emailaddressVal) || comment=='')

and earlier you have:

var comment_area = $("#comment_area").val(); //<-- 

change this to comment and it'll get past that at least.

EDIT: a little background. when firefox hits an error, sometimes it'll swallow it, and just stop running any javascript after that error, so your return false and or prevent default code isn't fire, so it's still going to post the form and refresh the page.

Change this line:

$(".submit").click(function () {

To this:

$("#comment_form").submit(function () {

The submit event gets triggered on the <form> element, not on the submit button.

Keep your damn code clean, so you can understand what you are cooking... This will work for you:

$(document).ready(function(){
    $("#comment_form").submit(function(e){
        e.preventDefault(); // stop refresh

        var name = $("#name").val();
        var email = $("#email").val();
        var comment_area = $("#comment_area").val();
        var dataString = 'name='+ name + '&email=' + email + '&comment_area=' + comment_area+'&submit_comment=true';
        var emailReg = /^([\w-\.]+@([\w-]+\.)+[\w-]{2,4})?$/;
        var emailaddressVal = $("#email").val();
        if(name=='' || !emailReg.test(emailaddressVal) || comment==''){
            alert('Please enter valid data and type in message');
        } else{
            $.ajax({
                type: "POST",
                url: "comments.php",
                data: dataString,
                cache: false,
                success: function(html){
                    $("#com_list").append(html);
                    $("#com_list").fadeIn("slow");
                    $("#flash").fadeOut('fast');
                }
            });
        }
    });
    $('#cancel').click(function(e){
        e.preventDefault();
        $('.slider').hide();
        $('#com_list').show();
    });
});

Here is some more clean code...

<div class="slider">
    <form id="comment_form" name="comment_form" method="post" action="#" enctype="multipart/form-data">
        <input type="text" id="name" name="name" maxlength="16"/>&nbsp;Name<br /><br/>
        <input type="text" id="email" name="email"/>&nbsp;Email&nbsp;(will not show)<br /><br/>
        <textarea id="comment_area" name="comment_area" maxlength="1000"></textarea><br /><br/>
        <input type="submit" class="submit" name="submit_comment" value="submit"/>&nbsp;&nbsp;comment or <a href="index.php" id="cancel"><u>cancel</u></a>
    </form>
</div>

Here is some other clean and SECURE code

<?php
if(isset($_POST['submit_comment'])){
    $name           =   mysql_real_escape_string($_POST['name']);
    $email          =   mysql_real_escape_string($_POST['email']);
    $comment_area   =   mysql_real_escape_string($_POST['comment_area']);
    //$lowercase    =   strtolower($email);
    //$image        =   md5( $lowercase );
    $query  =   'INSERT INTO comments (name,email,comment,com_date) '.
                "VALUES ('$name','$email','$comment_area',CURDATE())";
    $insert = mysqli_query($connect, $query);
}
?>