function GetTicker()
{
    var url     = '/include/idxticker.php';
    var pars    = '';
    var myAjax  = new Ajax.Request(
        url,
        {
            method : 'get',
            parameters : pars,
            onComplete : ShowTicker
        }
    );
}

function ShowTicker(originalRequest)
{
    var resText = originalRequest.responseText;
    var tickerElement = $('ticker');
    tickerElement.style.color = 'red';
    tickerElement.innerHTML = resText;
}

window.onload = function()
{
    GetTicker();
    setInterval(GetTicker,3000);
}