In all versions of FileMaker, Fields can be set to "slide up"and this will make the field disappear when empty. But layout text used to label the field will not be affected. The long standing solution is to replace the layout text with a calculation field that uses an If or case function to be empty when the data field it labels is empty.
In FileMaker 13, you can use the "hide when" setting in the inspector to hide the field and it's label when the field is empty.
Thanks, I'll try that shortly