Dearest Geeta,
Thank you for your loving letter inviting me to attend your birthday party on Saturday next in the evening. I send my heartiest congratulations and wish a very happy birthday. I regret to say that I shall not be able to attend the party.
You know my uncle is here from Bombay. He is returning to Bombay on next Saturday. We shall go to see him off at the Airport. I regret that I shall not be able to enjoy your sweet company.
Yours sincerely,