var arr_trailer = new Array();
arr_trailer[19] = "uploads/media/P1030067_ausschnitt_900x150_01.jpg";
arr_trailer[6] = "uploads/media/maintenance.jpg";
arr_trailer[5] = "uploads/media/trailer_trading.jpg";
arr_trailer[4] = "uploads/media/informatik.jpg";
arr_trailer[3] = "uploads/media/medical2.jpg";
arr_trailer[2] = "uploads/media/324425_150x900_01.jpg";
function preload()
{
for(count in arr_trailer)
    {
    preloaded[count] = new Image();
    preloaded[count].src=arr_trailer[count];
    }
}

function change(uid)
{
    setTimeout("dochange("+uid+")",500);
}

function dochange(uid)
{
    document.getElementById('trailer').src =  arr_trailer[uid] ;
}