`A` tag is not well-formed but why?

Question

Firebug is showing this HTML tag as "not well-formed":

<a id="aHarita" target="_blank" style="margin-left: 5px;" href="http://maps.google.com/maps?q=40.879236,29.386641&amp;num=1&amp;t=h&amp;sll=40.879132,29.386962&amp;sspn=0.006295,0.006295&amp;ie=UTF8&amp;ll=40.879317,29.386641&amp;spn=0.003022,0.006947&amp;z=18" >

Where is the problem?

Answer 1

The & in the href should be html encoded: &.

Answer 2

"target" is not a valid attribute for "a" tags.

Answer 3

You need to replace the & inside the attribute value by a reference like & or &, so:

<a id="aHarita" target="_blank" style="margin-left: 5px;" href="http://maps.google.com/maps?q=40.879236,29.386641&amp;amp;num=1&amp;amp;t=h&amp;amp;sll=40.879132,29.386962&amp;amp;sspn=0.006295,0.006295&amp;amp;ie=UTF8&amp;amp;ll=40.879317,29.386641&amp;amp;spn=0.003022,0.006947&amp;amp;z=18" >

Answer 4

Maybe you have to replace & with & in your href attribute.

Answer 5

There's a few things wrong with that, depending on your doctype. Run the page through http://validator.w3.org to get details on the validation failures. This is a good first stop for any validation problems, and should be useful for the future.