Sales Invoice (Charge Item)

Dear All

I have to create Sales invoice using Charge Item .I need to calculate the Sales Tax,Service Tax & Ecess.The Ecess is calculated as 1 % of Sales Tax. So i have created a structure for the calculation and also provided the Tax Setup.

The Ecess is given in the structure as 1 % of Sales Tax (Set the Base Formula & Calculation values in the Structure). But After calculating the Structure the Ecess is not getting calculated in the Structure Details.The Service Tax & Sales Tax is calculated properly. How can i solve this??Please help me out.

Thanks in Advance

Subha