public EditInfo getEditInfo(int n) {
	if (n == 0)
	    return new EditInfo(waveform == WF_DC ? "Voltage" :
				"Max Voltage", maxVoltage, -20, 20);
	if (n == 1) {
	    EditInfo ei =  new EditInfo("Waveform", waveform, -1, -1);
	    ei.choice = new Choice();
	    ei.choice.add("D/C");
	    ei.choice.add("A/C");
	    ei.choice.add("Square Wave");
	    ei.choice.add("Triangle");
	    ei.choice.add("Sawtooth");
	    ei.choice.add("Pulse");
	    ei.choice.select(waveform);
	    return ei;
	}
	if (waveform == WF_DC)
	    return null;
	if (n == 2)
	    return new EditInfo("Frequency (Hz)", frequency, 4, 500);
	if (n == 3)
	    return new EditInfo("DC Offset (V)", bias, -20, 20);
	if (n == 4)
	    return new EditInfo("Phase Offset (degrees)", phaseShift*180/pi,
				-180, 180).setDimensionless();
	if (n == 5 && waveform == WF_SQUARE)
	    return new EditInfo("Duty Cycle", dutyCycle*100, 0, 100).
		setDimensionless();
	return null;
    }