filtering messenger friend list for invite

[omerbutt]

hi there i am making a social community site in which i have to invite the messenger contacts by entering the user pass, i have done it right till grabbing the contacts but what i have to do now is to filter those addresss which already have an account on that site means i have two databases one that has the member emails of the site and other one that grabs the contacts of the user and puts it into
the datbase.now i am trying to compare these two databases that the contacts of the user that are already in the members database should not be invited. ihave used this query but itsnot working can anybody help in this regard
[code=php]
$sqlEP="select hotmail_email,m ember_email from hotmail_contact s,rage_members where (hotmail_contac ts.hotmail_emai l<>rage_members .member_email)" ;
$rsEP=mysql_que ry($sqlEP) or die(mysql_error ().'<br />'.$sqlEP);

[/code]

[debasisdas]

You need to pass ids from the first and pass the same to the second and use count to find out if that already exists.