var moveLayerTimer;
var moveLayerPas = 4;
var moveLayerElement = '';
var moveLayerButtonUp = '';
var moveLayerButtonDown = '';
function moveLayer(Sens) {
	Objet=document.getElementById(moveLayerElement);
    //document.getElementById(moveLayerButtonUp).style.visibility = "visible";
       
      if(parseInt(Objet.style.top) + (moveLayerPas*Sens)>0)  {
		clearTimeout(moveLayerTimer);
       	}
      else if(parseInt(Objet.style.top) + (moveLayerPas*Sens)<-(Objet.offsetHeight - Objet.parentNode.offsetHeight)) {
               //document.getElementById(moveLayerButtonDown).style.visibility = "hidden";
		clearTimeout(moveLayerTimer);
	}
      else {
        Objet.style.top = (parseInt(Objet.style.top) + (moveLayerPas*Sens)) + "px";
		moveLayerTimer = setTimeout("moveLayer(" + Sens + ");", 30);
	}
	
      
    /*if(Objet.style.top==0+"px"){
         document.getElementById(moveLayerButtonUp).style.visibility = "hidden";
         document.getElementById(moveLayerButtonDown).style.visibility = "visible";
	}
	else
	{
		document.getElementById(moveLayerButtonDown).style.visibility = "visible";
	}*/
}