var active_ID = "1";

  function imgAdj(imgDocID, mouseMov) {
      if ( mouseMov == "in"  && imgDocID != active_ID ) {
         document.images["M" + imgDocID].src = "images/btn_" + imgDocID + "_over.gif";
      }
      if ( mouseMov == "out" && imgDocID != active_ID ) {
         document.images["M" + imgDocID].src = "images/btn_" + imgDocID + ".gif";
      }
      if ( mouseMov == "cli" && imgDocID != active_ID ) {
         document.images["M" + imgDocID].src = "images/btn_" + imgDocID + "_over.gif";
         if (active_ID != "") {   document.images["M" + active_ID].src = "images/btn_" + active_ID + ".gif";  }
         active_ID = imgDocID;
      }
  }