How to end date a quotation line from front end

HI,

We are on R12.1.3. I would like to know how to end date a line on quotations. I know we can do it from back end. But I am trying to figure out a way for users to do from front end. As of now, when I create a new line for an existing item on the quote, it does not end date the previous line. I do not want to use price breaks, but still want to maintain old history of an item on the quote when price changes.

Thanks

Rajitha