Sub SetDockIconVisibility(TheApp as FolderItem, Visibility as Boolean)
 
   dim rf as resourceFork
   dim s as String
   dim HideIconString as String = "<key>NSUIElement</key>" + chr(13) + _
   "<string>1</string>" + chr(13)
   dim iInsertBefore as Integer
 
   if TheApp = nil or (not TheApp.exists) or TheApp.MacType <> "APPL"  then
     MsgBox "Application Error." + EndOfLine + EndofLine + _
     "Sorry, there was an error accessing the application."
     return
   end if
 
   rf = TheApp.OpenResourceFork
   if rf <> nil then
     s = rf.GetResource("plst", 0)
   else
     MsgBox "Error opening resource." + EndOfLine + EndofLine + _
     "The application may be running."
     rf.Close
     return
   end if
 
   if InStr(s, HideIconString) <> 0 and Visibility = true then
     s = ReplaceAll(s, HideIconString, "") // get rid of the line that hides the dock icon
     rf.AddResource(s, "plst", 0, "")
   elseif InStr(s, HideIconString) = 0 and Visibility = false then
     iInsertBefore = InStr(s, "</dict>" + chr(13) + "</plist>")
     If iInsertBefore = 0 then
       rf.Close
       MsgBox "Unexpected Error." + EndOfLine + EndofLine + _
       "Couldn't locate the end of the dictionary and the property  list."
       return
     end if
     s = left(s, iInsertBefore - 1) + HideIconString + mid(s, iInsertBefore)
     rf.AddResource(s, "plst", 0, "")
   end if
 
   rf.Close
 
   rf = TheApp.OpenResourceFork // see if we really wrote to it by closing and reopening it
   if rf <> nil then
     if rf.GetResource("plst", 0) <> s then
       MsgBox "Error saving resource." + EndOfLine + EndofLine + _
       "The application may be running."
       rf.Close
       return
     end if
   end if
   rf.close
 
End Sub