function ocat() {
    var millisec = 1000;
    var speed = Math.round(millisec / 100);
    var timer = 0;
    var lStart;
    var lEnd;
    var i;
    
    lStart = document.getElementById('s_cat').style.left;
    
    if (lStart == '-125px' || lStart == -125) {
      lStart = -125;
      lEnd = 0;
    } else if (lStart != -125 && lStart != '-125px') {
      lEnd = -125;
      lStart = 0;
    }

  if(lStart < lEnd) {
        for(i = lStart; i <= lEnd; i++) {
            setTimeout("document.getElementById('s_cat').style.left='"+i+"px'", (timer * speed));
            timer++;
        }
    } else if(lStart > lEnd) {
        for(i = lStart; i >= lEnd; i--) {
            setTimeout("document.getElementById('s_cat').style.left='"+i+"px'", (timer * speed));
            timer++;
        }
    }
}