search using checkboxes

[glennnphp]

i have values in two fields i want searched: Pulmonary PathologyRenal Pathology (table.specialty) and Chemical PathologyHematopathology (table.subspecialty)

I'm trying to search these two fields using a large number of checkboxes using

$checkbox1 = $_POST['specialty']; 
$string1 = '*'.@implode('*',$checkbox1).'*';

$checkbox2 = $_POST['subspecialty']; 
$string2 = '*'.@implode('*',$checkbox2).'*';


$sql="SELECT * FROM $tbl_user WHERE specialty LIKE '%$string1%' OR subspecialty LIKE '%$string2%' ORDER BY contact_name ASC";

if i search JUST Pulmonary Pathology or JUST Hematopathology i get my results, but if i search with terms that are NOT in the fields (Molecular Diagnostics) I get NO results.

Can someone show me how to get SOME of the data that's in a field using checkboxes... PLEASE? i've been on this all day...

my inputs look like:

    <LI><INPUT type="checkbox" name="subspecialty[]" value="Chemical Pathology">Chemical Pathology 
    <LI><INPUT type="checkbox" name="subspecialty[]" value="Hematopathology">Hematopathology 

Thanks
GN