function changeImgOn(element)
	{
  		if (element.tagName != "TD") return;
 			element.parentNode.cells[element.cellIndex - 1].style.backgroundImage = "url(img/bouton_spacer_o.gif)";
  			element.parentNode.cells[element.cellIndex + 1].style.backgroundImage = "url(img/bouton_spacer_o.gif)";
	}
	
	function changeImgOut(element)
	{
  		if (element.tagName != "TD") return;
 			element.parentNode.cells[element.cellIndex - 1].style.backgroundImage = "url(img/bouton_spacer.gif)";
  			element.parentNode.cells[element.cellIndex + 1].style.backgroundImage = "url(img/bouton_spacer.gif)";
	}