Discount Scales

Hi Experts,

I am having a business scenario like this :

We are having a discount based on quantity for example : for 1 to 100 MT discount is 10% but from 100 to 200 it is 20% , i have created a condition type for this one , can you please let me know the configuration steps for scales inside condition type so, that the system would calculate the percentage automatically..

Thnks

Sunny Sourav