如何将数字转换成文字表达？很急

很早以前写的，后来修正的版本找不到了...
<script>
var arr1=new Array(""," thousand"," million"," billion")
var arr2=new Array("zero","ten","twenty","thirty","forty","fifty","sixty","seventy","eighty","ninety")
var arr3=new Array("zero","one","two","three","four","five","six","sever","eight","nine");
var arr4=new Array("ten","eleven","twelve","thirteen","fourteen","fifteen","sixteen","seventeen","eighteen","nineteen");function Translate(num){
var len=num.length,i,j=0,strRet="";
var cols=Math.ceil(len/3);
var first=len-cols*3
var strRet=""
for(i=first;i<len;i+=3){
++j;
if(i>=0)
num3=num.substring(i,i+3)
else
num3=num.substring(0,first+3)
strEng=English(num3)
if(strEng!=""){
if(strRet!="") strRet+=","
strRet+=English(num3)+arr1[cols-j]
}
}
return strRet
}
function English(num){
strRet=""
if((num.length==3)&&(num.substr(0,3)!="000")){
if((num.substr(0,1)!="0")){
strRet+=arr3[num.substr(0,1)]+" hundred"
if(num.substr(1,2)!="00")strRet+=" and "
}
num=num.substring(1);
}
if((num.length==2)){
if((num.substr(0,1)=="0")){
num=num.substring(1)
}
else if((num.substr(0,1)=="1")){
strRet+=arr4[num.substr(1,2)]
}
else{
strRet+=arr2[num.substr(0,1)]
if(num.substr(1,1)!="0")strRet+="-"
num=num.substring(1)
}
}
if((num.length==1)&&(num.substr(0,1)!="0")){
strRet+=arr3[num.substr(0,1)]
}
return strRet;
}
</script>
<input id=number value=1234567890><input type=button value=Translate onclick=alert(Translate(document.all.number.value))>