var changing_thumbs = new Array();

function changeThumb(id, i, cThumbArray) {
  if (changing_thumbs[id]) {
    thumbArray = cThumbArray.split (',');
    document.getElementById(id).src = thumbArray[i];
    i++;
    if (i > thumbArray.length - 1) i = 0;
    setTimeout("changeThumb(" + id + "," + i + ", '"+thumbArray.toString()+"')", 500);
  }
}  


function startThumbChange(id, thumbArray) {  
  changing_thumbs[id] = true;
  changeThumb(id, 0, thumbArray.toString());
}

function stopThumbChange(id, thumbArray){
  changing_thumbs[id] = false;
    document.getElementById(id).src = thumbArray[0];
}