How do i open a specific site in any browser in my MacBook pro?

I am having problem to open an specific website in any browser .It was worked before but suddenly it is not working now.May be i have updated Firefox, i can't remember actually.that is the only change i made.mostly i use Firefox but i have tried to other browser like Chroma,safari,Internet Explorer but it is not opening.but it works on other pc or laptops.
Can any one help me with this problem?

Check the site at Down For Everyone Or Just Me -> Check if your website is down or up?. Maybe something's up with their server, not your computer.

Sorry, I should have read the whole message. Well, maybe the link could still help someone with a like problem.