How does Harper Lee use Dill in the novel?Quotes to back up points etc would be appreciated, thanks.

Dill, who is widely believed to be based on Harper Lee's
childhood friend, Truman Capote, provides some comic relief in a novel that is
intricately woven with some serious themes.  For example, the scene where the children
are trying to make Boo Radley come out; among other things, Dill suggests that they
offer to buy Boo an ice cream if he will appear.  Another ill-fated attempt involves
trying to get a note to him by means of a fishing pole.  Scout and Jem come to look
forward to Dill's arrival as part of the arrival of summer, and his departure is always
bittersweet, coming as it does as the end of summertime and the start of the school
year.  One year after he declares his undying love for Scout, she pronounces herself
devastated at his departure, and observes that she "stayed miserable for two
days."