still need 1 to 3 more sentences, help!

Question: identify and explain an example of dramatic irony in the play, "crossroads: a sad vaudeville". What is the purpose of dramatic irony in the story?

my answer: An example of dramatic irony in this story could be how the audience knew that the old women isn't the on the man is looking for. However, he doesn't realize it because he is expecting there to be a young and quite beautiful girl.