function montrer(id_layer)
						{
							t_layers = new Array('contenu','tpe','frais','avantages');
							for (i=0; i<t_layers.length;i++)
							{
								layer_contenu = document.getElementById(t_layers[i]);
								if (layer_contenu)
								{
									layer_onglet = document.getElementById(t_layers[i]+'_onglet');
									if (t_layers[i] == id_layer)
									{
										layer_contenu.style.display = "block";
										layer_onglet.className = "onglet_actif";
									}
									else
									{
										layer_contenu.style.display = "none";
										layer_onglet.className = "onglet_inactif";
									}
								}
							}
						}