Conflicting Javascript preventing form validation

im trying to validate a form before its submitted to the database but something seems to be conflicting with it and its just sending anyway without any values

heres my form:

<form method="post" action="send.php" id="theform" name="theform">
<input type="text" name="firstname" id="firstname" value="First Name" onFocus="this.value=''" class="yourinfo" ><br/>
<input type="text" name="lastname" id="lastname" value="Last Name" onFocus="this.value=''" class="yourinfo"><br/>
<input type="text" name="email" id="email" value="Email Address" onFocus="this.value=''" class="yourinfo"><br/>
<span style="color:#FFF; font-family:Arial, Helvetica, sans-serif; font-size:12px;">Ally McCoist will be sacked on</span>
<div id="datepicker"></div>
<input type="hidden" na开发者_StackOverflow中文版me="date" id="date">
<input type="image" src="images/submit-button-small.png" name="submit" id="submit" value="submit" style="margin-top:10px; margin-left:-2px;" >
</form>

heres my validate javascript:

$(document).ready(function(){
// Place ID's of all required fields here.
required = ["firstname", "lastname", "email"];
// If using an ID other than #email or #error then replace it here
email = $("#email");
errornotice = $("#error");
// The text to show up within a field when it is incorrect
emptyerror = "Please fill out this field.";
emailerror = "Please enter a valid e-mail.";

$("#theform").submit(function(e){                

    //Validate required fields
    for (i=0;i<required.length;i++) {
        var input = $('#'+required[i]);
        if ((input.val() == "") || (input.val() == emptyerror)) {
            input.addClass("needsfilled");
            input.val(emptyerror);
            errornotice.fadeIn(750);
        } else {
            input.removeClass("needsfilled");
        }
    }
    // Validate the e-mail.
    if (!/^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/.test(email.val())) {
        email.addClass("needsfilled");
        email.val(emailerror);
    }

    //if any inputs on the page have the class 'needsfilled' the form will not submit
    if ($(":input").hasClass("needsfilled")) {
         e.preventDefault();
    } else {
         errornotice.hide();
    }


});

// Clears any fields in the form when the user clicks on them
$(":input").focus(function(){       
   if ($(this).hasClass("needsfilled") ) {
        $(this).val("");
        $(this).removeClass("needsfilled");
   }
});
}); 

i also have this javascript on the page fore my jquery UI datepicker which i think might be causing the problem

<script>
        $(function() {
$("#datepicker").datepicker({
    altField: '#date'
});

$('#submit').click(function() {
    $('#output').html($('form').serialize());
});

});

fingers crossed one of you can see something that might fix this problem

It is possible that the form was filled out by a person with JavaScript disabled or that a person or machine simply invoked an HTTP POST, with whatever values they saw fit. For this reason, it is necessary to perform validation on the server-side (i.e. in send.php), not just on the client-side (in the JavaScript file). JavaScript validation is really just a UI optimization that allows a user to be immediately told that something is wrong without requiring a round-trip communication to the server. From a user-interface perspective, JavaScript validation is important, but from a security perspective it is useless.