... anchor "..." already defined

Cause:

An anchor with the same name is already defined. Each anchor should be unique.

Solution:

Choose another name for the anchor or modify the previous one.

Sample:

<form> anchor "my_form" already defined

BAD: <form name="my_form" action="test1.jsp"></form>
<form name="my_form" action="test2.jsp"></form>

GOOD: <form name="my_form1" action="test1.jsp"></form>
<form name="my_form2" action="test2.jsp"></form>

References:

Anchors: http://www.w3.org/TR/html4/struct/links.html#h-12.2.1