var nbimage= 20;
var width;
var height;
var url;
var gotosite= "index.php";
			
function banniere()
{
numimage= Math.round(Math.random()*(nbimage-1)+1);
if (numimage <= 10)
	{
	url = "/IMG/intro/intro-05.jpg";
	}
if (numimage > 10)
	{
	url = "/IMG/intro/intro-06.jpg";
	}
if (numimage > 11)
	{
	url = "/IMG/intro/intro-07.jpg";
	}
if (numimage > 12)
	{
	url = "/IMG/intro/intro-08.jpg";
	}
if(gotosite != "")
   	{
  	document.write ('<a href="' + gotosite + '">');
   	}		
	document.write('<img src="' + url + '" alt="Entrez !" border=0>')
if(gotosite != "")
   	{
   	document.write('</a>')
   	}
}