In this lesson we will see how to create a navigation bar which will allow us to navigate between the cards in our stack.

First create a new stack.

1. Select File -> New Stack -> iPhone
2. Open the Stack Insector and set the name to "NavigationExample"
3. Save your stack

A background group allows a control to be shared between cards. Because the Navigation Bar will appear on all the cards in the app and is used to show the user which card they are on sharing the widget across the cards is the best solution. It reduces the amount of code you need to write and the number of controls you need to create.

1. Select the Navigation Bar widget
2. Click the Group button in the Menubar
3. Open the Property Inspector for the group
   1. Set the name to "navigation"
   2. Check Shared group
   3. Check Behave like a background

Background groups are automatically placed on new cards.

The final step is to add code so the navigation bar switches cards when the user selects an item.

1. Select the navigation bar widget, you might need to select Select Grouped in the Menbar to allow you to select the widget and not the group.
2. Open the Code Editor for the navigation bar widget. You will see that the widget had a default hiliteChanged message.
3. Add the code to the Code Editor

on hiliteChanged
   go to card the hilitedItemName of me
end hiliteChanged

The hilitedItemName property returns the item name of the selected item. Because the names of our cards match the item names of the navigation bar you can use this property to navigate to the correct card.

Switch to Run mode and test the stack.