How to add current caller to queue

I like to create the following dialplan so that whoever dials the 3001 will be added the Sales queue:

exten => 3001,1,Answer
exten => 3001,n,AddQueueMember(Sales,${caller})
exten => 3001,n,Hangup

My question is: how to set caller variable ${caller} to the current caller, like SIP/alice if alice calls the extension?
Thanks for help.

Got it. Do not add the caller, default to current caller.