Dropdown in Grid

Question

Hi,
  i am developing a application in which iam using dropdown list,textbox controls in gridview. in the gridview first column(product id) i am placing dropdown list i.e all the rows of first column having dropdown list. in gridview 2nd and 3ed(name and address) column i am placing textboxes i.e in all the rows of column 2nd and 3ed. i am having table in database like address which is having column names as produci id, name, address. now what i wanted to do is i wil display all the product id's in all the dropdown list of gridview. after this user will select product id from gridview 1st row dropdown list, the corresponging values of product id should fetch from DB and display it 2nd and 3ed column of 1st row in gridview. like this same thing for 2nd row and so on. how to do this i am not getting. please can any body help me. Thanks in advance.