Q: how to remove viruses in my ipad ?

What 'problem' occurred?

Currently there's no known virus affecting iPad as long as you don't Jailbreak your iPad.

http://support.apple.com/kb/HT3743

Try this:

Settings>Safari>Clear History, Cookies and Data

There are no viruses on iPad!

Try reinstalling iOS 7

That's likely a very unnecessary step.  The OP needs to explain what the problem actually is.  It could be as simple as a website redirect, which is resolved simply by not going to that website anymore.

You're basically recommending an invasive surgery, when a couple of aspirin may be all that is needed.

Can you take a screenshot of the site and/or of the problem?

To make screenshots:

Press the Home button and the power button at the same time. This can be a little tricky at first.

Then post the result here

Thank you so much! Our old iPad (1) was stuck in a safari website that would not allow anything but pushing the "agree" button.  I did as you suggested, and it immediately freed everything up.