var alreadyClicked = false;
var phpsessid = null;



function navigImgs( avancement )
{
 contenuDiv = document.getElementById( 'navigation_imgs' ).value;
 var xhr_object = null;
 var data = null;
 
 if( window.XMLHttpRequest ) // Firefox
 {
  xhr_object = new XMLHttpRequest();
 }
 else if( window.ActiveXObject ) // Internet Explorer
 {
  xhr_object = new ActiveXObject( "Microsoft.XMLHTTP" );
 }
 else // XMLHttpRequest non supporté par le navigateur
 {
  alert( "Votre navigateur ne supporte pas les objets XMLHTTPRequest..." );
  //document.getElementById( 'navigation_imgs' ).innerHTML = contenuDiv;
  alreadyClicked = false;
  return;
 }
 
 data = "avancement=" + avancement;
 xhr_object.open( "POST", "/navigImgs.php", true );
 xhr_object.onreadystatechange = function()
                                 {
                                  if( xhr_object.readyState == 4 )
                                  {
                                   var tmp = xhr_object.responseText;
                                   if( tmp != "false" )
                                   {
                                    document.getElementById( 'navigation_imgs' ).innerHTML = tmp;
                                   }
                                   else
                                   {
                                    document.getElementById( 'navigation_imgs' ).innerHTML = contenuDiv;
                                   }
//                                   alert( tmp );
                                  }
                                 }
 xhr_object.setRequestHeader( "Content-type", "application/x-www-form-urlencoded" );
 xhr_object.send( data );
 alreadyClicked = false;
}