function showad( ) {
  document.getElementById("flowrap").style.visibility= "visible";
  document.getElementById("imgflow").style.visibility= "visible";
  document.getElementById("flowtxt").style.visibility= "visible";
  setTimeout ( "hidead()", 2600 );
}

function hidead( ) {
  document.getElementById("flowrap").style.visibility= "hidden";
  document.getElementById("imgflow").style.visibility= "hidden";
  document.getElementById("flowtxt").style.visibility= "hidden";
}