Edition to New rates

[MSK7]

Hello all ,

I am working for a site which sell products online.

the problem arises that -

After adding the no. of products to buy to Shopping cart

When a person change the quantity of no. of products on requirement

( inthe textbox of quantity) given in the List ,

the Rates does not change to New Rates after edition of quantity.

please suggest me how this edition can take place so that Rates also get

changed instantly to the New Rates , as the quantity of products is changed to New required quantity.

any suggestion will be appreciated.

Thanks & Regards.