First, the mysql_* functions are deprecated (see the warning notice at the top of the manual page for [man]mysql_fetch_array[/man]).
The error message means that what you got from [man]mysql_query[/man] was a boolean instead of a database result set. On the [man]mysql_query[/man] manual page is the statement:
For SELECT, SHOW, DESCRIBE, EXPLAIN and other statements returning resultset, mysql_query() returns a resource on success, or FALSE on error.
So that means that there was an error when you called [man]mysql_query[/man].
You need to find out what that error was. It's a good thing then that, on that same page, the "See Also" section has the line
[man]mysql_error/man - Returns the text of the error message from previous MySQL operation
So you should be able to use that to find out what the in your query was.
This FAQ provides a few more debugging tips.
