Suggestion on adding a set of controls to the page at a time

I am currently working on a advanced search page. Think of user can add as many criteria as they can before they hit the search button.
Initially, the page has one row of controls, let say, it starts with 2 dropdowns, and a text box across
then when the user click "Add", it will add another row/set of same control under it.
I would like to know what is the best approach to do it, should I create a table for this and then by adding a row the full set of controls will be added, or should I use repeater control?
The key thing is all the controls (dropdown and text boxes) should be editable at anytime. When user clicks "Add", the page would not lost any of the controls and previously selected value by the user.