Mail Merge in table and conditional formating

Hey guys,

I'm having trouble with a table that has mail merge fields in it.  I figured it out before some time ago but I can't remember how it's done.

The problem is:

In the table cell there is a mail merge field from an excel sheet.  If there is no value in the excel cell I'd like to return a 'No result given' in the word table.  At the moment it's giving me a zero value.  

I'm assuming its conditional formatting of a kind but I can't figure out how to do it.

All help appreciated!