timparker

/* JS fallback for HTML5 placeholder
 * requires jQuery and Modernizr (to detect support)
 * by Jon Raasch - @jonraasch - http://jonraasch.com/
 * modified script from Nico Hagenburger: http://bit.ly/LgrkT0
*/

if(!Modernizr.input.placeholder){
    $('[placeholder]').focus(function() {
        var input = $(this);
        if (input.val() == input.attr('placeholder')) {

timparker

// Only allow numbers in a text field

$(".class").keydown(function(event) {
  // Allow: backspace, delete, tab, escape, and enter
  if ( event.keyCode == 46 || event.keyCode == 8 || event.keyCode == 9 || event.keyCode == 27 || event.keyCode == 13 ||
      // Allow: Ctrl+A
    (event.keyCode == 65 && event.ctrlKey === true) ||
      // Allow: home, end, left, right
    (event.keyCode >= 35 && event.keyCode <= 39)) {
      // let it happen, don't do anything

timparker

<form>
  <div class="check">
    <input type="checkbox" value="None" id="newsletter" name="check" />
    <label for="newsletter"></label>
  </div>
</form>

form {
  input[type=checkbox] {
    visibility: hidden;