Reply Letter 'refusing the above invitation'. 

4/14, Padam Singh Colony,

New Delhi

16th Dec., 20___

My Dear Gagan,

I was glad to receive your kind letter. I am sorry to inform you that I am not in a position to attend the party. My mother is seriously ill. I attend to him day and night. I am really unlucky to miss such a happy company.

Yours sincerely,

Rohit Verma