I can't get mysql_field_name() to return the field name of
position 0 in the mysql result from my query. All subsiquent
field names appear, just not the first one. I even tried
just forcing a 0 in the position instead of the incremented
variable:

$result = mysql_query ( $sql );
while($db_content = mysql_fetch_row($result)) {
  for($i=0; $i < sizeof($db_content); $i++) {
    echo mysql_field_name($result, 0);
  }
}

That code doesn't output anything whereas if I replace the 0
in mysql_field_name() with $i, it prints the field names of
all but my first column.