var computeBtn = $('compute');
var c = 0;
var income = $('income');
if($('income').options[$('income').selectedIndex].value == '1')
	$('startMoney').disabled = false;
if(income){
	income.onchange = function(){
		var v = this.options[this.selectedIndex].value;
		if(v != '1'){
			$('startMoney').disabled = true;
			if(v == '9'){
				$('original').parentNode.style.display = 'block';
				$('expense').parentNode.style.display = 'block';
			}else{
				$('original').parentNode.style.display = 'none';
				$('expense').parentNode.style.display = 'none';
			}
		}else{
			$('startMoney').disabled = false;
			$('original').parentNode.style.display = 'none';
			$('expense').parentNode.style.display = 'none';
		}
	};
}

if(computeBtn){
	computeBtn.onclick = function(){
		var m = 0;
		try{
			m = parseInt($('money').value.replace(/[\D]*/i, ''));
		}catch(e){ alert('收入金额只能输入数字，请检查输入数据！');}
		if( m == 0 || $('money').value.replace(/^\s+|\s+$/i, '') == ''){
			alert('请先输入税前收入金额');
			$('money').focus();
		}else{
			var result = personaltaxCompute(m, $('income').options[$('income').selectedIndex].value);
			if(result != -1){
				$('tax').value = result.toString();
				$('endMoney').value = (m-result).toString();
			}
		}
	};
}

function personaltaxCompute(m, i){
	var s, r;
	r=0;
	if(i == '1'){
		m = m - parseInt($('startMoney').value);
		if (m<=1500) { c=3; s=0; }
		if ((1500<m) && (m<=4500)) { c=10; s=105; }
		if ((4500<m) && (m<=9000)) { c=20; s=555; }
		if ((9000<m) && (m<=35000)) { c=25; s=1005; }
		if ((35000<m) && (m<=55000)) { c=30; s=2755; }
		if ((55000<m) && (m<=80000)) { c=35; s=5505; }
		if (m>80000) { c=45; s=13505; }
		 r=(m*c)/100-s
		 if (r<0) r=0;
	}
	if(i == '2' || i == '3'){
		if (m<=5000) { c=5; s=0; }
		if ((5000<m) && (m<=10000)) { c=10; s=250; }
		if ((10000<m) && (m<=30000)) { c=20; s=1250; }
		if ((30000<m) && (m<=50000)) { c=30; s=4250; }
		if (50000<m) {c=35; s=6750; }
		 r=(m*c)/100-s;
		 if (m<0)	r=0;
	}
	if(i == '4'){
		if (m<=20000) { c=20; s=0; }
		if ((m>20000) && (m<=50000)) {	c=30; s=2000; }
		if (m>50000) { c=40; s=7000; }
		if (m<=4000) { m=m-800; }
		if (m>4000) { m=m-(m*20/100); }
		r=m*c/100-s;
		if (r<0) r=0;
	}
	if(i == '5'){
		if (m<=4000) { r=(m-2000)*20/100; }
		if (m>4000) { r=(m-(m*20/100))*20/100; }
		if (r<0)  r=0;
		r = r*70/100;
	}
	if(i == '6' || i == '8'){
		if (m<=4000) { r=(m-2000)*20/100; }
		if (m>4000) { r=(m-(m*20/100))*20/100; }
		if (r<0)  r=0;		
	}
	if(i == '7' || i == '10' || i == '11'){
		r = m*20/100;
	}
	if(i == '9'){
		s = m - parseInt($('original').value) - parseInt($('expense').value);
		if (s<0)
		{
			alert("都亏本了，不用交税了！");
			return(-1);
		}
		r = s*20/100;
	}
	return(r);
}