This is no longer a part of the World of Warcraft API. For alternatives, try Secure Templates or the /assist It was removed in patch 2.0.1.

Assists the specified player

AssistByName("playername");

Parameters Edit

Arguments Edit

("playername")

playername 

String - the name of the player to assist

DetailsEdit

This function cannot be used with non-player units (i.e. npc's or pets).