Question

I use this script to reload a DIV whose ID is news,

<script type="text/javascript">
    var auto_refresh = setInterval(function() {
        <? if ($lim >= 5) 
            $lim = 0;
        else 
            $lim = $lim + 2;

        if ($cnt == 1){
            $lim = 0; 
            $cnt += 1;
        } ?>

        $('#news').load('update.php?lim=<? echo $lim ?>');
    }, 10000); // refresh every 10000 milliseconds
</script>

The update.php containts this code to receive the value for lim,

$lim=$_GET['lim'];

But after every 10 seconds the ‘lim’ value is sent as 0. I need to update the ‘lim’ value based on the condition in the script.

I checked in update.php for $lim value using echo command. Always it is 0. What is the bug in my code?

Answer 1

You seem a little confused as to what is serverside/clientside. $lim is a PHP variable, so is only available on the server side. You need to change your logic over to be javascript. Try this:

var lim = <? echo $lim ?>; // assuming lim is always a number this will work.
var cnt = 0; // just guessed at what this should be initially.
var auto_refresh = setInterval(function() {
    if (lim >= 5) 
        lim = 0;
    else 
        lim = lim + 2;

    if (cnt == 1){
        lim = 0; 
        cnt += 1;
    }

    $('#news').load('update.php?lim=' + lim);
}, 10000); // refresh every 10000 milliseconds

Alternatively you could change the logic to make an AJAX request on each iteration of the timer which passes the lim variable to your PHP and receives back the new value.