function jackpotCounter(counterId)
{
    // increment settings in cents
    var incrementMin = 2;
    var incrementMax = 5;
    // interval settings in milliseconds
    var intervalMin = 2000;
    var intervalMax = 3500;

    var amount = jackpot[counterId];
    if (amount > 0)
    {
        amount = parseFloat(amount) + parseFloat((Math.floor(Math.random() * (incrementMax - incrementMin)) + incrementMin) / 100);
        if (amount.toFixed(2))
            amount = amount.toFixed(2);
        jackpot[counterId] = amount;
    
        document.getElementById(counterId).innerHTML = '$' + jcAddCommas(amount);
    
        if (jcTimeout[counterId])
            clearTimeout(jcTimeout[counterId]);
        jcTimeout[counterId] = setTimeout("jackpotCounter('" + counterId + "')", (Math.round(Math.random() * (intervalMax - intervalMin))) + intervalMin);
    }
}

function jcAddCommas(strValue)
{
  var objRegExp  = new RegExp('(-?[0-9]+)([0-9]{3})');

  //check for match to search criteria
  while(objRegExp.test(strValue)) {
     //replace original string with first group match,
     //a comma, then second group match
     strValue = strValue.replace(objRegExp, '$1,$2');
  }

  return strValue;
}