Call javascript function on submit form

Question

I am trying to call JavaScript function while submitting the form.

Here is code but while submitting function not called, please suggest something and I want to show error messages using javascript method as well , how can I show error messages in validation using JavaScript.

<form id="register" name="register"  onsubmit="validateForm()">
<label for="Username"> Username </label><br>
<input type="text" class="register-control" id="Username" name="Username" placeholder="Enter Username"> <br><br>
<label for="Password"> Password </label><br>
<input type="password" class="register-control" id="Password" name="Password" placeholder="Enter Password"><br><br>
<label for="Confirm-Password"> Confirm Password </label><br>
<input type="password" class="register-control" id="Confirm-Password" name="Confirm-Password" placeholder="Confirm Password" ><br><br>

<label for="email"> Email </label><br>
<input type="email" class="register-control" id="email" name="email" placeholder="Enter Valid Email"><br><br>
<button type="submit">Submit</button>

</form>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.5.2/jquery.min.js"></script>
 <script type="text/javascript" src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.8/jquery.validate.min.js"></script>
<script type="text/javascript">
$(document).ready(function () {
    $("#register").validate({
        rules: {
            "Username": {
                required: true,
            },
            "Password": {
                required: true,
                minlength: 5
            },
            "Confirm-Password": {
                required: true,
            },
            "email": {
                required: true,
            }
        }
    });
});
</script>

and here is JavaScript code

function validateForm()
{
    var password = document.forms["register"]["Password"].value;
    var con-password = document.forms["register"]["Confirm-Password"].value;
    if(password != con-password)
    {
        document.getElementById('password-error').style.visibility='visible';
        alert("not matched");
    }
    alert("matched");
}

Answer 1

This is probably due to a syntax error in your script. When you see errors like that, look into the JavaScript console of your browser.

In this case, con-password is not a valid variable name. What JavaScript sees is:

var con - password ...

i.e. the code says "substract password from con". Try an underscore instead:

var con_password ...