function activity(pos_x){
  
  document.writeln("<div id=\"jsWaitMessage\" style=\"font-family: Verdana; font-size: 10px; text-align: center; padding: 3px; position: absolute; left: 30%; top:" + pos_x + "; height: 20px; width: 300px; z-index:3\"></div>"); 
  document.writeln("<div id=\"jsWaitArea\" style=\"display: none; position: absolute; left: 30%; top: " + pos_x + "; height: 20px; width: 300px; border: 1px black solid; background: #FFFFAA;z-index:2\">"); 
  document.writeln("<div id=\"jsWaitBlock\" style=\"position: relative; left: 0px; height: 20px; width: 50px; background: blue;z-index:2\"></div>"); 
  document.writeln("</div>"); 
   
  jsWait_defaultInstance = null; 
  }
  
  function showWait(message) 
  { 
      jsWait_defaultInstance = new jsWait('jsWait_defaultInstance', message); 
      jsWait_defaultInstance.show(); 
  } 
   
  // ------------------------------------------- 
  //        Définition du type jsWait 
  // ------------------------------------------- 
   
  /** 
   * Constructeur 
   * @param name le nom du composant 
   * @param message le message a afficher 
   */ 
  function jsWait(name, message) 
  { 
      this.name = name; 
      this.message = message; 
      this.speed = 10; 
      this.direction = 2; 
     
      this.waiting = false; 
     
      this.divMessage = document.getElementById("jsWaitMessage"); 
      this.divArea = document.getElementById("jsWaitArea"); 
      this.divBlock = document.getElementById("jsWaitBlock"); 
  } 
   
   
  // ------------------------------------------- 
  //        Méthodes publiques 
  // ------------------------------------------- 
   
  jsWait.prototype.show = function() 
  { 
      this.divMessage.innerHTML = this.message; 
      this.divMessage.style.display = "block"; 
      this.divArea.style.display = "block"; 
      this.divBlock.style.display = "block"; 
      this.divBlock.style.left = "0px"; 
      this.waiting = true; 
       
      this.loop(); 
  } 
   
  jsWait.prototype.setMessage = function(message) 
  { 
      this.message = message; 
      this.divMessage.innerHTML = this.message; 
  } 
   
  jsWait.prototype.stop = function() 
  { 
      this.waiting = false; 
      this.divMessage.style.display = "none"; 
      this.divArea.style.display = "none"; 
      this.divBlock.style.display = "none"; 
  } 
   
   
  // ------------------------------------------- 
  //        Méthodes privées 
  // ------------------------------------------- 
   
  jsWait.prototype.loop = function() 
  { 
      myLeft = this.divBlock.style.left; 
      myLeft = myLeft.substring(0, myLeft.length-2); 
      intLeft = parseInt(myLeft); 
     
      if(intLeft >= 250) 
          this.direction = -2; 
      if(intLeft <= 0) 
          this.direction = 2; 
     
      myLeft = "" + (intLeft+this.direction) + "px"; 
      this.divBlock.style.left = myLeft; 
     
      if(this.waiting) 
          setTimeout(this.name + ".loop()", this.speed); 
  } 
   
  function process_img(msg,id_span,id_img){
	document.getElementById('img_dl').src='../edt/images/download.gif';
      document.getElementById(id_span).innerHTML = msg +' : ';
  }
  function process_img2(img,id_img){
    document.getElementById(id_img).src = img;
  }