function fCalc(frm){
	var Num=frm.Num.value,
		cFrom=frm.cFrom.value,
		cTo=frm.cTo.value
		frm.Total.value=fCalcCurrency(cFrom, cTo ,Num )
}
function fCalcCurrency(cFrom,cTo,Num){
	if(!cFrom || !cTo) return
	if(Num && /^\d+$/.test(Num)){
		Num=(Num * cFrom)/cTo
		Num=(Num+"")
		var len=
		Num=Num.substr(0, (Num.indexOf(".")==-1?Num.length:Num.indexOf(".")) +3)
		return fCommaFormat(Num)
	}
}