$(document).ready(function(){
	$('.captcha').click(function() {
      var src = this.src + "";
      var pos = src.search(/\?/);
      if (pos > 0) {
          src = src.substr(0, pos);
      }
      var now = new Date();
      this.src = src + '?' + now.getTime();      
  })
  .css('cursor', 'pointer');
});