Multiple Search

i need to make some choices in my search code by adding 1 drop-down box or more like that

<SELECT size=1 name="items">
<OPTION selected value="all" >all</OPTION>
<OPTION value="1" >item 1</OPTION>
<OPTION value="2" >item 2</OPTION>
<OPTION value="3" >item3</OPTION>
<OPTION value="4" >item 4</OPTION>

</SELECT>
so my search string will be
select * from table where rs("itemID") = '"&items&"'

and my quiz is if i want 2 make the drop-down box (items) = all i mean i want the sql statment sellects all of the names what should b the value of the all option ?

note im using 3 or 4 drop-down box and i may nedd the value of some of them to b all and the othere takes any value.