Need help with Luhn check

I need to output 350 employee numbers with a Luhn number at the end of the string.
I found this site: http://imei.sms.eu.sk/ This is almost what I want, but with this code I only can implement one string at a time, so with 350 numbers it will take time. Do anyone know how I can insert all the 350 employee numbers at once and get the Luhn number at the end of the string?

Source code:

 // Javascript code copyright 2009 by Fiach Reid : www.webtropy.com
 // This code may be used freely, as long as this copyright notice is intact.
 function Calculate(Luhn)
 {
    var sum = 0;
    for (i=0; i<Luhn.length; i++ )
    {
        sum += parseInt(Luhn.substring(i,i+1));
    }
    var delta = new Array (0,1,2,3,4,-4,-3,-2,-1,0);
    for (i=Luhn.length-1; i>=0; i-=2 )
    {        
        var deltaIndex = parseInt(Luhn.substring(i,i+1));
        var deltaValue = delta[deltaIndex];    
        sum += deltaValue;
    }    
    var mod10 = sum % 10;
    mod10 = 10 - mod10;    
    if (mod10==10)
    {        
        mod10=0;
    }
    return mod10;
 }

 function Validate(Luhn)
 {
    var LuhnDigit = parseInt(Luhn.substring(Luhn.length-1,Luhn.length));
    var LuhnLess = Luhn.substring(0,Luhn.length-1);
    if (Calculate(LuhnLess)==parseInt(LuhnDigit))
    {
        return true;
    }    
    return false;
 }

Code (markup):