// ***************************************************************
// Fonction scroll sur boutons (move + defilement)
// ***************************************************************

 function move(contenu,contenant,direction)
{
  var x = parseInt(contenu.style.top);
  var deplacement = contenu.offsetHeight-contenant.offsetHeight;
  
  if (direction > 0)
  {
    if (x >= 0) {direction = 0};
  }
  else
  {
    if (x <= -deplacement ) {direction = 0};
  }
  x = x + direction;
  contenu.style.top = x + 'px';
  //document.getElementById('test').value = contenu.offsetTop;
}

// On récupère les paramètres de la fonction defilement

function defilement(id_contenu,id_contenant,id_bouton1,id_bouton2)
{
  var direction = 0;
  var contenant = document.getElementById(id_contenant);
  var contenu = document.getElementById(id_contenu);
  var bouton1 = document.getElementById(id_bouton1);
  var bouton2 = document.getElementById(id_bouton2);
  
  contenu.style.top = '0px';
  
  // On change le pas de direction au survol des boutons 1 et 2
  
  bouton1.onmouseover = function () {direction = - 10};
  bouton1.onmouseout = function () {direction = 0};
  bouton2.onmouseover = function () {direction = 10};
  bouton2.onmouseout = function () {direction = 0};
  window.setInterval(function() {move(contenu,contenant,direction)},60);
}