Number to word converter

Visualforce code :

<apex:page controller="Numbertowordclass">

  <apex:form >

  <apex:pageBlock id="pb" >

  <apex:panelGrid columns="2">

   Enter Number:<apex:inputText value="{!num}" size="60"/>

   Enter word:<apex:inputText value="{!wrd}" size="60"/> 

  </apex:panelGrid>

  <apex:pageBlockButtons >

  <apex:commandButton value="Convert" action="{!convert}" reRender="pb"/>

  <apex:commandButton value="Cancel" action="{!Cancel}" reRender="pb"/>

  </apex:pageBlockButtons>

  </apex:pageBlock>

  </apex:form>

</apex:page>

Apex  code :

//This Class will support upto 12 digits :-

public with sharing class Numbertowordclass {

    public void Refresh(){

    num= null;

    wrd= null;

    }

    public PageReference Cancel() {

        Refresh();

        return null;

    }

    public string wrd{set;get;}

    public long num { get; set; }

  

    public string convert() {

      wrd=convert(num);

      return null;

    }

    public String[] units = new String[]{'Zero ','One ','Two ','Three ','Four ','Five ','Six ','Seven ','Eight ','Nine

        ','Ten ', 'Eleven ','Twelve ','Thirteen ','Fourteen ','Fifteen ', 'Sixteen ','Seventeen ','Eighteen ',

        'Nineteen '};

    public String[] tens = new String[]{'','','Twenty','Thirty','Forty','Fifty','Sixty','Seventy','Eighty','Ninety'};

 

    //This method is used to convert the integer to words

    public  String convert(long i) {

      //

      if( i < 20)  return units[integer.valueOf(i)];

      if( i < 100) return tens[integer.valueOf(i)/10] + ((math.mod(i , 10) > 0)? '' + convert(math.mod(i , 

         10)):'');

      if( i < 1000) return units[integer.valueOf(i)/100] + ' Hundred ' + ((math.mod(i , 100) > 0)?' ' + 

        convert(math.mod(i , 100)):'');

      if( i < 10000) return units[integer.valueOf(i)/1000] + ' Thousand ' + ((math.mod(i , 1000) > 0)?' ' + 

        convert(math.mod(i , 1000)):'');

      if( i < 1000000) return convert(i / 1000) + ' Thousand ' + ((math.mod(i , 1000) > 0)? '' +  

         convert(math.mod(i ,1000)):'') ;

      if(i < 100000000) return convert(i / 1000000) + ' Milion ' + ((math.mod(i , 1000000) > 0)? '' + 

        convert(math.mod(i , 1000000)):'') ;

      if(i < 1000000000) return convert(i / 1000000) + 'Milion ' + ((math.mod(i , 1000000) > 0)? '' + 

        convert(math.mod(i , 1000000)):'') ;    

      return convert(i / 1000000000) + ' Bilian ' + ((math.mod(i , 1000000000) > 0)? '' + 

        convert(math.mod(i , 1000000000)):'') ;

}

}