Conversation search 2.7

Conversation search v1.7 changes:

Now works with XF v2.1 and newer.

Conversation search v1.6 changes:

Added Recipients column to results page.

Conversation search v1.5 changes:

Added ability to search on username alone.

Conversation search v1.4 changes:

Deleted unused phrases.

Conversation search v1.3 changes:

Added check for proper username entry.

Conversation search v1.2 changes:

Updated PHP file.

Conversation search v1.1 changes:

Changed position of Conversation search link.