SOS: Select box autochange script

[Samuell]

Hi, everybody!
I'm trying to make this script - http://www.w3schools.com/php/php_ajax_database.asp
roll it's fields from the first to the last automatically
the code i have at the moment

function roller() {
var total=3;//number of options
 for (var i=0;i<total;i++) { 
  setTimeout("roll("+i+")", (3000*(i+1)));
 }
 setTimeout("roller()", (3000*total));
}
function roll(i) { 
document.usersform.users[i].fireEvent("onchange")
}
 

do not work an couse an error.
please, how make this work?

[wyatt]

I believe that running setTimeout ends the current function. Instead, I suggest the following:

function roller(i) {
    var total = 3;
    var i = i : 0;
    roll(i);
 
    setTimeout("roller("+((i+1)%total)+")",3000);
}
 

Essentially, each time, the function 'roller' is run, a value 'i' is passed to it, which increases by one every time the function runs. However, if it reaches the total, it rolls back to 0 (the '%' modulo operator). If you call roller without passing a value for 'i', it will default to 0.