W3C compliance issue

W3C compliance issue with the following line.

<a href="http://visitor.r20.constantcontact.com/d.jsp?llr=u6nm85dab&p=oi&m=1103768205236" target="_blank"><img src="images/send.png" alt="send button" width="131" height="40" class="center"/></a>

I tested the page in the Validator link below.  You can see all the issues that are all appearing on line 152 of my page.  I received the code from constant contact.  How do I fix this as it's clearly not W3C compliant.

Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Well, the validator clearly tells you that the problem is a non-escaped "&".  You can check the chart for URL encoding sequnces here: http://www.w3schools.com/tags/ref_urlencode.asp, but unless you have some serious regulatory compliance issues, I'd leave it be.
Scott FellDeveloper & EE ModeratorCommented:
Run the validator again.  This time check all the options and you can clean up with htmltidy.  The link converts to

<a href="http://visitor.r20.constantcontact.com/d.jsp?llr=u6nm85dab&amp;p=oi&amp;m=1103768205236" target="_blank"><img src="images/send.png" alt="send button" width="131" height="40" class="center"></a>

Open in new window

and no validates

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Ray PaseurCommented:
Try using the HTML5 doctype declaration.  It looks to me like the validator is confused about a URL.  Not sure why, but maybe the experimental doctype will help it get past the issue.  The HTML looks valid to me.
Chris StanyonWebDevCommented:
On line 148, the querystring part of your Anchors href includes a couple of & symbols. For your document to validate you need to change those to &amp;
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.