How do assign String value into Issue Comment?

[Ramesh Lakshmanasamy]

I want assign string value into Issue Comment.its throw exception.

[Nic Brough -Adaptavist-]

We can't help you with a statement like that.  I could say "I want a kitten", and you would not be able to help me because you don't know why I have not gone and got one myself.

  You need to tell us what you are doing and maybe what the error is.