How to equal dropdownlist item value with something in if statement

Hi,
I have dropdownlist which inclue like below
     Mac
       1
       2
       3
But when i try to put in if condition
let say mac = '2'
if(mac == ddl.items.toString())  //// but this condition is not work out
how to get condition if mac is one of the ddllistitems value.
Please can anyone give me idea. Thanks.