PHP: Generate List of U.S. State Abbreviations

For form select listbox populating...

function StateCodes($deft) {
    $clist = "AL,AK,AS,AZ,AR,CA,CO,CT,DC,DE,FL,GA,HI,IA,ID,IL,IN,"
    . "KS,KY,LA,MA,MD,ME,MI,MN,MO,MS,MT,NC,ND,NE,NH,NJ,NM,NY,"
    . "OH,OK,OR,PA,RI,SC,SD,TN,TX,UT,VA,VT,WA,WI,WV,WY";
    $tok = strtok($clist, ",");
    while ($tok != false) {
        if ($deft == $tok) {
            echo "$tok\n";
        }
        else {
            echo "$tok\n";
        }
        $tok = strtok(",");
    }
}