Mysql query returns null value

I have code that runs two mysql queries. The second query depends on the result of the first returning true. This works fine, that is to say the value of $result is true and the code moves to the next query. However when the second query runs, which it does and works, it returns a null value for $result.
In testing the code I added some echo statements. The first just shows the value "RESULT". The second, Records deleted showed a -1 value for the affected rows, when in fact one record was deleted. As I said, the both queries work fine.
Can someone tell me why the result value for the second query is null and why the number of record affect = -1?

Thanks,
Tom

$query = DeleteTerm($TermID);
$result = mysql_query($query);
if ($result)
{
$query = DeleteTermFromGroupTermLink($TermID);
$result = mysql_query($query);
echo "RESULT " . $rc . "<br/>";
echo "Records deleted: ", mysql_affected_rows();
if ($result)
{
$lblMessage = "Delete Term Was Successful.";
}
else
{
$lblErrMessage = "Delete Term Encountered An Error. Please Try Again.";
}
}
else
{
$lblErrMessage = "Delete Term Encountered An Error. Please Try Again.";
}

You might want to show the two functions you use, assuming they 'contain' the SQL that is run.

1) Please enclose your code in [ PHP ] tags. See the sticky at the top of the forum.
2) You should not be using the MySQL extensions. Switch to PDO and add some error checking.
3) The -1 indicates the previous query failed.
4) If the previous query is really a DELETE then it must return either true or false. You are misinterpreting null for false.

Ah, but the query did not fail and there is lies the mystery. The record/s did indeed get deleted. That said, I think I found the problem. The table the from which the record was being deleted had two fields, each a key field (linking table). The delete query passed in a value for only one of the two fields, which was my error. When I corrected the query to pass both key fields as parameters I got a good return code = 1. To be honest I'm still not sure why I got the bad return code. I ran the original code in phpMyadmin and it worked fine.
At this point I can only assume someone up above was tying to let me know what a knucklehead I was not passing in two parameters.

Thanks for you help,
Tom