Eventhandlers Key events
	//Event handlers    public void keyAction(KeyEvent e)    {         char c = e.getKeyChar(); //handy substitutions         if (c == '*') c = 'x';         else if (c == 'p') c = '+'; //enable the Enter keys         else if (c == '\n' || c==141)                 c = '=';         else if (c == 'c') c = '%';         st = c + "";         if (c == 'q') st = SQRT;         else st = c + "";         doAction(st);    }