Basic SQL syntax

OK, I got a simple search page working (thanks to all of you who helped me). Another simple question for you. If I had a search and the data to be searched needs to be determined by check boxes, How would I write the sql>? Like this? $sql = "SELECT * FROM table WHERE town LIKE '%$search_data%' OR street LIKE '%$search_data%' "; Is "OR" even the correct syntax? Here's how I tried it, which didn't give any results..... (Where reference is the id number (or map reference) and search_data is the text field for users to tpye the query. if ($reference != "") $search_reference = "OR id LIKE '%$reference%'"; } $sql = "SELECT * FROM table WHERE town LIKE '%$search_data%' $search_reference"; $result = @mysql_query($sql,$connection) or die (mysql_error()); $num = mysql_num_rows($result); TIA, James.