Code:
if reaper.CountSelectedTracks(0) == 2 then name1 = ({reaper.GetSetMediaTrackInfo_String( reaper.GetSelectedTrack(0,0), "P_NAME", '', 0 )})[2]
reaper.GetSetMediaTrackInfo_String( reaper.GetSelectedTrack(0,0), "P_NAME", ({reaper.GetSetMediaTrackInfo_String( reaper.GetSelectedTrack(0,1), "P_NAME", '', 0 )})[2], 1 )
reaper.GetSetMediaTrackInfo_String( reaper.GetSelectedTrack(0,1), "P_NAME", name1 , 1) end