Warning: mysql_num_rows(): supplied argument is not a valid MySQL result resourc

[MDanz]

what i've done is i have one query in one place on the page.  i've copied and paste it to another place on the page and now this error comes up.  When i delete the copy it works again?.. any ideas, i don't need to post the code.. just need a guess on why this is happening, i'm assuming a duplicate value or something.

[fenway]

Check mysql_error() after the offending query.