Tactical Command and Challenge Missions??

[RocknKiwi]

Im puzzled as in how to jion a Tactical Command game or Team up with some1 to do a Challenge Missions, any help? silly me its probably stearing me right in the face ,

Also how do i find my id: numbers ###?
Thz

[protoswarrior]

Mouse over it on the top right hand corner of your Profile page on bnet, where you see your name appear.

[Alzarath]

I believe Challenge missions are only single player.