I'm Sorry I Haven't a Clue pause in the middle of speaking, a reference to Radio 4's other long-running panel show "Just a Minute". (Likewise, occasionally on "Just a Minute", a panellist will make a challenge of "Mornington Crescent".) Chairman Jack Dee frequently pokes fun at "Just a Minute", particularly its chairman Nicholas Parsons, whom he mimics in constantly emphasising the long experience of some panellists, and the fact that the programme can be heard all over the world. The programme has won the Gold Sony Radio Comedy Award three times: Other awards: "Clue" has been broadcast since 11 April 1972 on BBC Radio 4 with
Master I. A. M. of Zwolle Aurifaber Meester" (Master John the Goldsmith), possibly Johannes Ludolphi, a goldsmith who arrived in Zwolle in 1479. One variation of this theory supposes that the signature contains the marks of both artists: I. A. M. would be Johann van den Minnesten's signature, while the image of a drill is the hallmark of the goldsmith / engraver. This collaborative theory would explain the vast differences in composition between the still and simple "The Madonna Seated, the Christ Child Holding the Cross" and the manneristically dynamic "The Betrayal of Christ". Master I. A. M. produced original and inventive compositions in a style