shiping problem

how to setup next shiping option

-under 100$ shiping is 10$
-for 100$ and more shiping is free

I search for extenzion but nothing like this .

My version opencart is 1.4.9.3

Use both the Flat Rate shipping method (set at $10) and the Free Shipping method (with the Total field set to $100).

Ok this is helpfull but in this case if the basket under 100$ flat rate shiping is still there! and customer is little confused
---but I will write message "if your basket case is under 100$ shiping is free!"
maybe there is some extenzion for shiping
if basket > 100$ (example) flat rate shiping is gone ! and there is only choice free shiping

A lot of people have requested this, but there's no way to do it currently. I don't think it's a bad thing...if you set the sort order for Free Shipping to show up first, it'll be automatically selected. AND the customer gets to see the value they're getting in Free Shipping, which I think is psychologically good for how they view the sale.

Ok thanks
I do it on this way.