Holds software program name presented to the server.

A String value.  

object.UserAgent [= value]

The UserAgent Property syntax has these parts:

When UserAgent property is set, it provides information about program used by the client to the server. This is for statistical purposes and the tracing of protocol violations.

The first white space delimited word must be the software product name, with an optional slash and version designator. Other products which form part of the user agent may be put as separate words.

This property is just a 'shortcut' to Request.Headers("User-Agent") value.