[Daniel Seltzer as Cohn and Neil Flanagan as Abe in "Knock Knock".]
[Neil Flanagan as Abe and Daniel Seltzer as Cohn in "Knock Knock".]
[Nancy Snyder as Joan, Neil Flanagan as Abe and Daniel Seltzer as Cohn in "Knock Knock".]
[Neil Flanagan as Abe in "Knock Knock".]
[Daniel Seltzer as Cohn in "Knock Knock".]
[Daniel Seltzer as Cohn and Nancy Snyder as Joan in "Knock Knock".]
[Jules Feiffer and the cast of "Knock Knock".]
["Knock Knock" theater still.]
[Curtain call for "Knock Knock".]
[John Heffernan as Abe and Charles Durning as Cohn in "Knock Knock".]
[John Heffernan as Abe in "Knock Knock".]