function show( id )
{
   try
   {
      document.getElementById( id ).style.display = "block";
   }
   catch (e)
   {
      // ignore
   }
}

function hide( id )
{
   try
   {
      document.getElementById( id ).style.display = "none";
   }
   catch (e)
   {
      // ignore
   }
}  

function hideAll()
{

   hide( "calgary" );
   hide( "halifax" );
   hide("mississauga");
   hide("montreal");
   hide("ottawa");
   hide("quebec");
   hide("toronto");
   hide("vancouver");

  
}

function showAll()
{
   show( "calgary" );
   show( "halifax" );
   show("mississauga");
   show("montreal");
   show("ottawa");
   show("quebec");
   show("toronto");
   show("vancouver");
}