where do i put it?

/* TODO: make this function looks good in somewhere else, please forgive me for plece it here :( */
function getSymbol($alphabet)
{
    if($alphabet == 'p'  || $alphabet == 'p+')
        $s = "+";
    else if($alphabet == 'e')
        $s = "=";
    else if($alphabet == 'm' || $alphabet == 'm-')
        $s = "-";
    else if($alphabet == 'q')
        $s = "?";
    else if($alphabet == 'b')
        $s = "";
    else if($alphabet == '' || $alphabet == ' '){
        $s = "";
    }
    return $s;
}