_removeClass = function(element, value) {
    var c, cl, className, classNames = [];
    if (typeof value === "string" && value) {
      classNames = value.split(/\s+/);
    }
    if (element && element.nodeType === 1 && classNames.length > 0) {
      if (element.className) {
        className = (" " + element.className + " ").replace(/[\t\r\n\f]/g, " ");
        for (c = 0, cl = classNames.length; c < cl; c++) {
          className = className.replace(" " + classNames[c] + " ", " ");
        }
        className = className.replace(/^\s+|\s+$/g, "");
        if (className !== element.className) {
          element.className = className;
        }
      }
    }
    return element;
  }
Remove a class from an element, if it has it.

@returns The element, with its class removed.
@private