Client side validation not working with button


I'm trying to get the client side validation working. I'm getting the errors i expected, but xval doesn't seem to catch the post when i press the submit button in my form.
The only thing i can thing off that could cause the problem is the fact that i'm using an HTML button;
Something like <button class="save" type="submit" name="save" onclick="$('#buttonClicked').val('save');"><span>Opslaan</span></button>
instead of <input type="submit" value="submit" />
Could this be the issue, and if yes how can i solve it?