whole_func_string: function addClass(el, name) {
          if (!hasClass(el, name)) {
            el.className = el.className ? [el.className, name].join(' ') : name;
          }
      }
func_code_string: function addClass(el, name) {
          if (!hasClass(el, name)) {
            el.className = el.className ? [el.className, name].join(' ') : name;
          }
      }
func_documentation_string: addClass: add the css class for the element.