var xhr = null; 
function getXhr()
{
     if(window.XMLHttpRequest)xhr = new XMLHttpRequest(); 
else if(window.ActiveXObject)
  { 
  try{
     xhr = new ActiveXObject("Msxml2.XMLHTTP");
     } catch (e) 
     {
     xhr = new ActiveXObject("Microsoft.XMLHTTP");
     }
  }
else 
  {
  alert("Votre navigateur ne supporte pas les objets XMLHTTPRequest..."); 
  xhr = false; 
  } 
}
 
function ShowPage(page)
{
getXhr();
xhr.onreadystatechange = function()
    {
     if(xhr.readyState == 4 && xhr.status == 200)
     {
     document.getElementById("contenu").innerHTML=xhr.responseText;
     } else
	// chargement
        document.getElementById("contenu").innerHTML="<div style='width:"+largeur+"px; height:"+hauteur+"px; background-color:white;'><table style='width:"+largeur+"px; height:"+hauteur+"px;' align=center><tr align=center><td valign=middle><br/> <img src='images/ajax-loader.gif' alt=''></img></td></tr></table>";	 
    }
hauteur=document.getElementById("contenu").offsetHeight;	
largeur=document.getElementById("contenu").offsetWidth - 20;
xhr.open("GET","./"+page+".html",true);
xhr.send(null);

}

function Exit(page)
{
getXhr();
xhr.onreadystatechange = function()
    {
     if(xhr.readyState == 4 && xhr.status == 200)
     {
     document.getElementById("body").innerHTML=xhr.responseText;
     }
    }
xhr.open("GET","ajax.php?page="+page,true);
xhr.send(null);

}