var xs, xd, doc_width, doc_height = document.body.clientHeight ;
  
  doc_width = document.body.clientWidth ; 
  xs = 0;  xd = doc_width - 300 ;
  
  document.write("<div id=sinistra class=fiocco>" + 
      "<table bgcolor=#980E0E height=110 width=300>" +
      "<tr><td align=center valign=middle class=arco>" +
      "ARCO" +
      "</td></tr></table></div>");
  document.write("<div id=destra   class=fiocco>" + 
      "<table bgcolor=#980E0E height=110 width=300>" +
      "<tr><td align=center valign=middle class=arco>" +
      "ACUTO" +
      "</td></tr></table></div>");
  document.getElementById("sinistra").style.top = 10;
  document.getElementById("destra").style.top = 10;
  
  function neve() {  
    
    xs += 1 ; xd -= 1 ;
    document.getElementById("sinistra").style.left = xs ;
    document.getElementById("destra").style.left = xd ;
    
    if ( xd - 230 > xs ) { setTimeout( "neve()" , 5 ) };
  }
  neve() ;