How to give access to delete his own comments I am using Drupal 7 and want user should be able to delete his own comment. I know that is it not supported by drupal 7 due to threading. 
You can provide edit permission from "admin/people/permissions" but there is no option to provide permission of delete.

Thanks in Advance

Ref : https://www.drupal.org/node/777696
Are you familiar with coding? You can try this tutorial.

edit: and i ran into this site, wich is a patch to the module 'Comment Goodness'. There's also some extra info about flat comments (the default structure is nested, not flat).