[jQuery] Jquery Validation plugin doesn't working on ASP NET MVC

[Edgar Méndez .]

I'm trying to use the Jquery Validation plugin on aspnet mvc
fframework but it doesn't work, when I open the firebug console it
display an error:

jQuery is not defined
[Break on this error] jQuery.extend(jQuery.fn, {\n

I don´t know how to fix this issue an had already added the
jquery-1.3.2.js to my scripts, there is the valdiation code I'm using:

<script type="text/javascript" src="../../Scripts/
jquery.validate.js"></script>
    <script type="text/javascript" src="../../Scripts/
jquery-1.3.2.js"></script>

  <script type="text/javascript">
  $(document).ready(function(){
    $("#simpleSignUp").validate();
  });
  </script>

    <form id="simpleSignUpForm" action="" method="get">
        <input type="text" id="firstname" class="required"
minlength="2"/>
        <input type="text" id="lastname" class="required"
minlength="2"/>
        <input type="text" id="username" class="required"
minlength="2"/>
        <input type="text" id="email" class="required email"
minlength="2"/>
        <input type="text" id="password" class="required"
minlength="8" />
        <input type="text" id="website" class="url" />
                <input type="submit" value="Submit" />
</form>

Any help will be very appreciate,

Thanks in advance...