Setting layout preferences
Layout preferences affect the way you work in Layout mode.
To set layout preferences:
Windows: Choose Edit menu > Preferences.
OS X: Choose FileMaker Pro menu > Preferences.
In the Preferences dialog box, click the Layout tab, and then set the options you want to use.
Select Always lock layout tools.
Add new fields you define to the bottom of the current layout
Select Add newly defined fields to current layout.
Select Save layout changes automatically (do not ask).
Related topics 
Selecting and working with objects on a layout
Adding fields to a layout