comedies

[chrissie8]

British playwright famous for lighthearted comedy

[Buenchico]

There are dozens of possible candidates.

However, this guy must be near the top of the list:
http://www.alanayckbourn.net/

Chris

[Schutzengel]

Could it be Alan Ayckbourn - wrote comedy plays about middle class morals

[vehelpfulguy]

Noel Coward ?

Alan Bennett ?

(Not sure either are "lighthearted" but they certainly included comedy in their output)