//除法
function accDiv(arg1,arg2){
	var t1=0,t2=0,r1,r2;
	try{t1=arg1.toString().split(".")[1].length}catch(e){}
	try{t2=arg2.toString().split(".")[1].length}catch(e){}
	with(Math){
		r1=Number(arg1.toString().replace(".",""))
		r2=Number(arg2.toString().replace(".",""))
		return (r1/r2)*pow(10,t2-t1);
	}
}
Number.prototype.div = function (arg){
	return accDiv(this, arg);
}


//乘法
function accMul(arg1,arg2){
	var m=0,s1=arg1.toString(),s2=arg2.toString();
	try{m+=s1.split(".")[1].length}catch(e){}
	try{m+=s2.split(".")[1].length}catch(e){}
	return Number(s1.replace(".",""))*Number(s2.replace(".",""))/Math.pow(10,m);
}
Number.prototype.mul = function (arg){
	return accMul(arg, this);
}


//加法
function accAdd(arg1,arg2){
	var r1,r2,m;
	try{r1=arg1.toString().split(".")[1].length}catch(e){r1=0}
	try{r2=arg2.toString().split(".")[1].length}catch(e){r2=0}
	m=Math.pow(10,Math.max(r1,r2))
	return (arg1*m+arg2*m)/m
}
Number.prototype.add = function (arg){
	return accAdd(arg,this);
}


//减法
function accMin(arg1,arg2){
	var r1,r2,m;
	try{r1=arg1.toString().split(".")[1].length}catch(e){r1=0}
	try{r2=arg2.toString().split(".")[1].length}catch(e){r2=0}
	m=Math.pow(10,Math.max(r1,r2))
	return (arg1*m-arg2*m)/m
}
Number.prototype.min = function (arg){
	return accMin(arg,this);
}

//保留4位小数
function formatFlt4(flt) { 
	if(parseFloat(flt) == flt){
		return Math.round(flt * 10000) / 10000;
	}else{
		return flt;
	}
}

//保留2位小数
function formatFlt2(flt){
	if(parseFloat(flt) == flt){
		return Math.round(flt * 100) / 100;
	}else{
		return flt;
	}
}