As previously mentioned in the Filling in forms section, you can use Ctrl+F11 to jump back and forth between form objects: Ctrl+F11 takes you to the next form object and Ctrl+Shift+F11 takes you to the previous one.
In form mode, you also have the option of using Tab and Shift+Tab to perform these functions.
The order in which you jump among the form objects can be specified with the ribbon command Insert | Form object | Tab order.
Choose this command to open the "Tab order" dialog box. In the list Objects, select the form object whose position you want to change in the tab order. Then click on one of the arrow buttons to the right of the list to move the object up or down in the list. The position of the object in the tab order changes accordingly.
Use the Rearrange button to restore the original order.