Parsing Error : Content is not allowed in prolog.

I am getting an error when trying to parse an xml file in java and I request to anybody to say about that ,the error is

Parsing Error : Content is not allowed in prolog.

Line : 1

Column : 1

org.xml.sax.SAXException: Parsing Error : Content is not allowed in prolog.

Line : 1

Column : 1

[329 byte] By [Reply_mea] at [2007-11-26 21:03:38]