var result = element.charCode; element.charCode = value;
The charCode property represents the character code during the onkeypress event and the unmodified scan code of the key during onkeydown and onkeyup events. To detect whether the Alt, Ctrl, Meta, or Shift key is also pressed, see the altKey, ctrlKey, metaKey, or shiftKey property of the event. The charCode property is provided for compatibility only. The latest version of the Document Object Model (DOM) Events specification defines a key property instead.
There are no standards that apply here.
Microsoft Developer Network: [Windows Internet Explorer API reference Article]