var t = 0;
var x = 0;
var dx = 10;
function moveRofls()
{
    var rofls = $$("img[src$='rofl.gif'][class='smile']");
    if (!rofls.length) return;
    for (i=0; i<rofls.length; i++)
    {
        rofls[i].style.left = x + "px";
    }

    x += dx;
    if ((x > $$(".messages-content")[0].getWidth()-200) || (x<0))
    {
        dx *= -1;
        x += dx;
    }

}

function startMoving()
{
    if (t) return;
    t = setInterval(moveRofls, 100);
}

function stopMoving()
{
    if (!t) return;
    clearInterval(t)
    t = 0;

    var rofls = $$("img[src$='rofl.gif'][class='smile']");
    if (!rofls.length) return;
    for (i=0; i<rofls.length; i++)
    {
        rofls[i].style.left = "0px";
    }

}

startMoving()