preview before print interaction of type letter

hanaa

After having created a segment, in the segment window itself i want to make an interaction of type letter created in mail merge with my contacts in the segment. Normally after having created the interaction, and i click log, i have to check any required check boxes (send attachment and create follow up segment) , after having done so and i click ok, the letters are printed with the names of my contacts on it . How can i have a preview of the letters with the names of my contacts on it before the letters are printed????