function display_drop_down () {
  var style = document.getElementById('drop_down').style.display;
  if(style == 'none'){
    document.getElementById('drop_down').style.display = 'block';
  }else{
    document.getElementById('drop_down').style.display = 'none';
  }
}

function get_width () {
  return document.getElementById('clients_logos').offsetWidth;
}

function move_clients (direction) {
  var current_left = 0;
  var width = get_width();
  if(direction == 0){
    current_left = document.getElementById('clients_logos').offsetLeft;

    if(current_left > ((width - document.getElementById('overflow_box').offsetWidth)*-1)){
      var myTween = new Tween(document.getElementById('clients_logos').style,'left',Tween.EaseOut,current_left,(current_left-300),0.5,'px');
      myTween.onMotionStarted = function () {
        document.getElementById('right_link').disabled = true;
      };
      myTween.onMotionFinished = function(){
        document.getElementById('right_link').disabled = false;
      };
      myTween.start();
    }
      
  }else{
    current_left = document.getElementById('clients_logos').offsetLeft;

    if(current_left < 0){
      var myTween = new Tween(document.getElementById('clients_logos').style,'left',Tween.EaseOut,current_left,(current_left+300),0.5,'px');
      myTween.onMotionStarted = function () {
        document.getElementById('left_link').disabled = true;
      };
      myTween.onMotionFinished = function(){
        document.getElementById('left_link').disabled = false;
      };
      myTween.start();
    }
  }
}