function isModifierKey(oEvent) {
			var sKey = oEvent.key; // based on KeyBoardEvent.key (https://www.w3.org/TR/uievents/) and (https://www.w3.org/TR/uievents-key/)
			return (sKey === 'Shift') ||
				(sKey === 'Control') ||
				(sKey === 'Alt') || // Modern browsers uses 'Alt' for left 'Alt' key and 'AltGraph' for right 'Alt Gr' key
				(sKey === 'AltGraph') || // see above -^
				(sKey === 'CapsLock') ||
				(sKey === 'NumLock');
		}
Detect whether the pressed key is a modifier.

Modifier keys are considered:
SHIFT, CONTROL, ALT, ALTGRAPH, CAPS_LOCK, NUM_LOCK
These keys don't send characters, but modify the characters sent by other keys.

@param {jQuery.Event} oEvent The event object of the <code>keydown</code>, <code>keyup</code> or <code>keypress</code> events.
@static
@returns {boolean} True if a modifier key was pressed