function getObj(name)
{
  if (document.getElementById)
  {
  	this.obj = document.getElementById(name);
	this.style = document.getElementById(name).style;
  }
  else if (document.all)
  {
	this.obj = document.all[name];
	this.style = document.all[name].style;
  }
  else if (document.layers)
  {
   	this.obj = document.layers[name];
   	this.style = document.layers[name];
  }
}

function effetDiv(calque, quand){
	// recup du calque multi browsers
	var qc = new getObj(calque);
	// et hop go go go go
	switch (quand){
		case 'over' :
			qc.style.mozOpacity = '0.75';
			break;
		case 'out' :
			qc.style.mozOpacity = '1';
			break;
		}
}