[liorean]

A: After quite some optimisation, you could end up with a function looking something like this:

Number.prototype.toOrdinal=function(m){
    return (this +
        ["th","st","nd","rd"][(!(
            ((m=this%10) >3) ||
            (Math.floor(this%100/10)==1)
        ))*m]);
}

and you use it like this:

var
    nNumber=12,
    sFirstOrdinal=nNumber.toOrdinal(), // => '12th'
    sSecondOrdinal=(22).toOrdinal(); // => '22nd'

Well, I won't bore you with the development procedure of this very slick and optimised function. You can check it out yourself in this thread.