code: function crossBrowser(property, value, prefix) {
  
      function ucase(string) {
        return string.charAt(0).toUpperCase() + string.slice(1);
      }
  
      var vendor = ['webkit', 'moz', 'ms', 'o'],
        properties = {};
  
      for (var i = 0; i < vendor.length; i++) {
        if (prefix) {
          value = value.replace(prefix, '-' + vendor[i] + '-' + prefix);
        }
        properties[ucase(vendor[i]) + ucase(property)] = value;
      }
      properties[property] = value;
  
      return properties;
    }
docs: function for adding vendor prefixes