0 down vote favorite http://developer.apple.com/library/...r.html#//apple_ref/doc/uid/TP40009984-CH6-SW2 When you use custom subclasses in your interface, or add outlets and actions to a controller, you can use Assistant to work on your interface design and your interface code at the same time. To do so, select your nib file in the project navigator to open Interface Builder and click the Assistant button to open the Assistant editor pane. If the Assistant editor does not automatically display the header file you want, use the Assistant editor pane jump bar to select the source file containing the controller code for the object. Figure 4-8 shows a window with a graphic view selected in Interface Builder and the header file for the graphic view being chosen from the Automatic mode of Assistant. By default, the Assistant editor pane is displayed below the Interface Builder editor. Choose View > Assistant Layout to switch between a vertical or horizontal split for the two editor panes. Now, where the hell is this Assistant button to open the Assistant Editor pane? http://developer.apple.com/library/...al/iPhone101/Articles/05_ConfiguringView.html 1. In Xcode, select the view controller’s nib file (MyViewController.xib). 2. Display the Assistant editor. 3. Make sure Assistant displays the view controller’s header file (MyViewController.h). 4. Control drag from the button in the nib file to the method declaration area in the header file. How to do step 2? How to display "the" Assistant Editor?