message = 
  "To measure and outline a selection, enable \"Add to overlay\"\n"
  +"in Analyze>Set Mesurements and press \"m\" (Analyze>Measure).\n \n"
  +"Use the Overlay>Remove Overlay command to remove the outlines.\n"
  +"Set the outline color and line width using Image>Overlay>Overlay Options.\n"
  +"Enable/disable numeric labels using Image>Overlay>Labels."

  showMessage("Measure and Label", message);