Modify php script to allow multiple countdowns within one page.

Hi, I have the following php countdown script that counts down to a date and time. Please see the below example:

<SCRIPT language="JavaScript" SRC="countdown.php?timezone=US/Pacific&countto=2011-06-25 00:00:00&do=t&data=Sorry, This Offer Has Expired."></SCRIPT>

And countdown.php:


<?php
// we will be sending Javascript codes
header('Content-Type: text/javascript'); 

// select the timezone for your countdown
$timezone = trim($_GET['timezone']);
putenv("TZ=$timezone");

// Counting down to New Year's on 2020
$countdown_to = trim($_GET['countto']); // 24-Hour Format: YYYY-MM-DD HH:MM:SS"

// Getting the current time
$count_from = date("Y-m-d H:i:s"); // current time -- NO NEED TO CHANGE

// Date difference function. Will be using below
function datediff($interval, $datefrom, $dateto, $using_timestamps = false) {
  /*
    $interval can be:
    yyyy - Number of full years
    q - Number of full quarters
    m - Number of full months
    y - Difference between day numbers
      (eg 1st Jan 2004 is "1", the first day. 2nd Feb 2003 is "33". The datediff is "-32".)
    d - Number of full days
    w - Number of full weekdays
    ww - Number of full weeks
    h - Number of full hours
    n - Number of full minutes
    s - Number of full seconds (default)
  */
  
  if (!$using_timestamps) {
    $datefrom = strtotime($datefrom, 0);
    $dateto = strtotime($dateto, 0);
  }
  $difference = $dateto - $datefrom; // Difference in seconds
   
  switch($interval) {
   
    case 'yyyy': // Number of full years

      $years_difference = floor($difference / 31536000);
      if (mktime(date("H", $datefrom), date("i", $datefrom), date("s", $datefrom), date("n", $datefrom), date("j", $datefrom), date("Y", $datefrom)+$years_difference) > $dateto) {
        $years_difference--;
      }
      if (mktime(date("H", $dateto), date("i", $dateto), date("s", $dateto), date("n", $dateto), date("j", $dateto), date("Y", $dateto)-($years_difference+1)) > $datefrom) {
        $years_difference++;
      }
      $datediff = $years_difference;
      break;

    case "q": // Number of full quarters

      $quarters_difference = floor($difference / 8035200);
      while (mktime(date("H", $datefrom), date("i", $datefrom), date("s", $datefrom), date("n", $datefrom)+($quarters_difference*3), date("j", $dateto), date("Y", $datefrom)) < $dateto) {
        $months_difference++;
      }
      $quarters_difference--;
      $datediff = $quarters_difference;
      break;

    case "m": // Number of full months

      $months_difference = floor($difference / 2678400);
      while (mktime(date("H", $datefrom), date("i", $datefrom), date("s", $datefrom), date("n", $datefrom)+($months_difference), date("j", $dateto), date("Y", $datefrom)) < $dateto) {
        $months_difference++;
      }
      $months_difference--;
      $datediff = $months_difference;
      break;

    case 'y': // Difference between day numbers

      $datediff = date("z", $dateto) - date("z", $datefrom);
      break;

    case "d": // Number of full days

      $datediff = floor($difference / 86400);
      break;

    case "w": // Number of full weekdays

      $days_difference = floor($difference / 86400);
      $weeks_difference = floor($days_difference / 7); // Complete weeks
      $first_day = date("w", $datefrom);
      $days_remainder = floor($days_difference % 7);
      $odd_days = $first_day + $days_remainder; // Do we have a Saturday or Sunday in the remainder?
      if ($odd_days > 7) { // Sunday
        $days_remainder--;
      }
      if ($odd_days > 6) { // Saturday
        $days_remainder--;
      }
      $datediff = ($weeks_difference * 5) + $days_remainder;
      break;

    case "ww": // Number of full weeks

      $datediff = floor($difference / 604800);
      break;

    case "h": // Number of full hours

      $datediff = floor($difference / 3600);
      break;

    case "n": // Number of full minutes

      $datediff = floor($difference / 60);
      break;

    default: // Number of full seconds (default)

      $datediff = $difference;
      break;
  }    

  return $datediff;
}

// getting Date difference in SECONDS
$diff = datediff("s", $count_from, $countdown_to);
?>

// Here's where the Javascript starts
countdown = <?=$diff?>;

// Converting date difference from seconds to actual time
function convert_to_time(secs)
{
	secs = parseInt(secs);	
	hh = secs / 3600;	
	hh = parseInt(hh);	
	mmt = secs - (hh * 3600);	
	mm = mmt / 60;	
	mm = parseInt(mm);	
	ss = mmt - (mm * 60);	
		
	if (hh > 23)	
	{	
	   dd = hh / 24;	
	   dd = parseInt(dd);	
	   hh = hh - (dd * 24);	
	} else { dd = 0; }	
		
	if (ss < 10) { ss = "0"+ss; }	
	if (mm < 10) { mm = "0"+mm; }	
	if (hh < 10) { hh = "0"+hh; }	
	if (dd == 0) { return (hh+":"+mm+":"+ss); }	
	else {	
		if (dd > 1) { return (dd+" days "+hh+":"+mm+":"+ss); }
		else { return (dd+" day "+hh+":"+mm+":"+ss); }
	}	
}

// Our function that will do the actual countdown
function do_cd()
{
	if (countdown < 0)	
	{ 	
		<?php
			if(strtolower(trim($_GET['do'])) == 'r' )
			{
		?>
		// redirect web page
		document.location.href = "<?=$_GET['data']?>";
		<?php } ?>

		<?php
			if(strtolower(trim($_GET['do'])) == 't' )
			{
		?>
		// change text
		document.getElementById('cd').innerHTML = "<?=$_GET['data']?>";
		<?php } ?>

	}	
	else	
	{	
		document.getElementById('cd').innerHTML = convert_to_time(countdown);
		setTimeout('do_cd()', 1000);
	}	
	countdown = countdown - 1;	
}

document.write("<div id='cd'></div>\n");

do_cd();

<? exit(); ?>

can someone tell me how I can modify this script to allow it to be used in multiple places on one page. It does not work properly when you have more than on countdown per page.

Thanks in advance!

You need to declare new variables in each context, so they do not fight for more global ones, such as if each was an object and all settings and variables were stored internal to the object, set at or near construction time.