//this function centers the layer in the window
function centerLayer(name){
   if (document.layers) {
      document.layers[name].left=window.pageXOffset+(window.innerWidth-300)/2;
      document.layers[name].top=window.pageYOffset+(window.innerHeight-100)/2-100;
      }
   else { 
	    //document.getElementById(name).style.left=window.document.body.scrollLeft+(window.document.body.clientWidth - 300)/2;
    	//document.getElementById(name).style.top=window.document.body.scrollTop+(window.document.body.clientHeight-100)/2-50;     
    	document.getElementById(name).style.left=400;
    	document.getElementById(name).style.top=200;     
      }
}


//this function shows or hides a layer 
function showLayer(name,show){
   if (document.layers) {
      if (show) document.layers[name].visibility="visible";
	  else document.layers[name].visibility="hidden";
     }
   else { 
	    if (show) document.getElementById(name).style.visibility="visible";
	    else document.getElementById(name).style.visibility="hidden";
      }
}

//coche toutes les chekbox d'un formulaire passé en paramètre
function checkAllCheckbox(form){
	var e = form.elements;
	for (var i = 0; i < e.length; i++) {
		if (e[i].type == 'checkbox') {
			e[i].checked = true;
			e[i].onclick();
		}
	}
}