function culc_deduction() {
    f = document.forms[0];
		var income = f.fincome.value;
		var fee    = f.ffee.value;
		var exception = 100000;
		if (f.fincome <= 2000000)
		  // ”NŽû200–œˆÈ‰º
		  exception = ffincome.value * 0.05;
		
		// �T�œŠzŒvŽZ
	  var deduction = (fee - exception) * income;
		
		// �T�œŠz‚Ì�Å‘å‚Í�A200–œ
		if (deduction > 2000000)
		  deduction = 2000000;
		else
		if (deduction < 0)
		  deduction = 0;
			
		f.fdeduction.value = deduction;
	}