If I am using Firefox what kind of add-on are available which can find bugs in a website?

Hello Prasad,
Thaanks for helping me .I will use selenium IDE first.
Then I will try other methods given in the link.

What is Sed?

Thanks

We can vote on all posts using the "Vote: *****" controls (with 5 stars) you can see.

The vote of 5 means excellent, 4 — good, and so on, 1 — very bad. 4-5 are considered up-votes, add points to the reputation of original author, 1-3 are down-votes, they reduce reputation points.

—SA

Thanks .