From the File Menu, select View, and choose Properties window from the drop-down list or click on the Properties window icon in the toolbar. The Properties window will be displayed on the desktop.
Click on a Label control in the design window to display its properties. The Properties window is also displayed when you drag and drop the Label Control onto the Format.
You can now set the properties for the selected Label control in the window as shown below.

Working with Field Controls | Setting Control Properties | Complete Property Listing | Label Class | Label Class Properties