Select the object you are trying to apply a name to, then click on the name tag icon on the infobar.
Enter the required name in the 'Apply name:' field, or if the name has already been applied elsewhere in the document, select it from the drop down list.
This article applies to:
Xtreme 4, Xtreme Pro 4, Xtreme 5, Xtreme Pro 5, Photo & Graphic Designer 6 and later, Designer Pro 6 and later
Web Designer 5 and later