// JavaScript functions to show and hide drop-down menus.

// In SimpleNavBar.html we call ShowMenuDiv each time the mouse goes over 

// either the menu title or the submenu itself, and call HideMenuDiv when the

// mouse goes out of the menu title or the submenu iteslf (onMouseOut).



function ShowItem (itemID) {

  var x = document.getElementById(itemID);

  if (x)

    x.style.visibility = "visible";

  return true;

}



function HideItem (itemID) { 

  var x = document.getElementById(itemID);

  if (x)

     x.style.visibility = "hidden";

  return true;

}



//    As noted in the SimpleNavBarStyles.css file, using x.style.visibility as

//    seen below seemed to have better cross browser support than using 

//    x.style.display="block" and x.style.display="none" to show and hide 

//    the menu.