Basically, when composing a tv interview the basic conventions of the form are:
* orientation - where, why , what..
*salutation - audience and interviewee(s)
*Q n A format
*converys information and comment
*shows interaction - the interviewer should respond to comments made and frame questions in response
*sign off - concluding remarks
*lead to next program/links
^ the above all from 'Success in HSC advanced english" by susan and bruce pattinson
You should also include techniques which distinguish are TV interview from a radio interview. For example, use camera shots, music, commercials to convey to the marker that you are in fact writing a tv talk show.