Form ajax submit

<form name='myForm' id='myForm' action='../examples/demo_form_ajax.php' type='multipart/form-data'>
    <fieldset class='pFieldset'><legend>Form ajax submit</legend><br/>
        <label class='pLabel' for='myname'>Name: </label>
            <input type='text' name='myname' id='myname' value='John Smith'/><br/>
        <label class='pLabel' for='email'>Email: </label>
            <input type='text' name='email' id='email' value='test@test.com'/><br/>
        <label class='pLabel' for='file_upload'>Image: </label>
            <input type='file' style='height: 23px' id='file_upload' name='file_upload'/><br/>
        <label class='pLabel' for='newsletter'>Newsletter: </label>
            <input type='checkbox' name='newsletter' id='newsletter' value='true'/><br/>
        <label class='pLabel' for='spam'>Spam: </label>
            Yes<input type='radio' name='spam' id='spam1' value='true'/>
            No <input type='radio' name='spam' id='spam2' value='false'/><br/>
        <button type='submit'id='submit_button'>Submit</button><br/>
    </fieldset>
</form>