Here is the login form from your page
<form action="http://www.seniorsearch.com/content/sign" class="webform-client-form" id="signin">
<div id="webform-component-name">
<input type="hidden" value="0" id="fb_login_id" name="submitted[fb_login_id]">
<input type="hidden" value="" id="redirect_url" name="submitted[redirect_url]">
<input type="text" class="form-text name1" maxlength="128" size="60" value="" name="submitted[name]" id="edit-submitted-name" placeholder="Enter Email">
</div>
<div id="webform-component-pass">
<input type="password" class="form-text pass1" id="password" name="submitted[pass]" placeholder="Enter Password" maxlength="128" size="60" value="" >
<input type="hidden" value="" name="details[sid]" id="sid">
<input type="hidden" value="1" name="details[page_num]" id="page_num">
<input type="hidden" value="1" name="details[page_count]" id="page_count">
<input type="hidden" value="0" name="details[finished]" id="finished">
<input type="hidden" value="form-_OBf1JYKx79Qg5_hsPtYAWmCPrRX6DwFKSODz4M7Wk4" name="form_build_id" id="form_build_id">
<input type="hidden" value="webform_client_form_52" name="form_id" id="form_id">
<input type="hidden" value="webform-ajax-wrapper-52" name="webform_ajax_wrapper_id" id="webform_ajax_wrapper_id">
</div>
<input type="submit" value="" name="op" class="form-submit ajax-processed" id="submit"><span class="termss">I accept Senior Search's Terms of Use.</span>
</form>
You need to send every one of those parameters with your AJAX script if you want the login to work.