having problems with mysql statement where and or based on user input -

$query = "select username, email, password, salt            tbl_memembers            (username = $resetuser) or (email = $resetuser)"; 

this keeps returning there nothing in database, when know fact there matching details entered ($resetuser = $_post previous page)

try query

 $query = "select username, email, password, salt            tbl_memembers            username = '$resetuser'  email = '$resetuser' ";