how add reduction of the product's price automa?

[stepby]

Sorry for my english! )

 

Look! We have the price on product!

 

It is necessary to reduce the price automatically.

 

example:

 

today is 1.07.2005 and the price of product is 1000 dollars

 

I set the possible price 800 and finaly date of action 1.08.2005

 

and I say I want that the boots will reduce every days (the step are 5 dollars )

 

buyers of page can look this product (goods) everyday , but the price drop down as 1.08.2005 becomes available

 

Do you know such contribite(module)?