Add javascript to simple html form

Hi, I'm looking for a JavaScript programmer with experience programming html forms. I have a simple html form (at the bottom of this text), when you press submit the javascript should verify all the input fields are not empty. if any field is empty the error message div should be displayed. when a person press submit the information from the form should be sendt to a php document at another server for example: [login to view URL] when the form is submitted the person should stay on the page and not be redirected to the [login to view URL] site if the form is successfully sent, hide the "form1" div and show the "thankyou" div <div id="form1"> <form action="[login to view URL]" method="post"> First name:<br> <input type="text" name="firstname"><br> Last name:<br> <input type="text" name="lastname"><br> zip code:<br> <input type="text" name="zip"><br> e-mail:<br> <input type="text" name="email"><br> <br><br> <input type="submit" value="Submit"> </form> </div> <div id="thankyou" style="display:none;"> thank you message </div> <div id="errormessage" style="display:none;"> please fill inn all the fields </div>