Senario 1: there is a databound control on the page, for example, a Repeater, and for every row, there is a Delete button/link. Senario 2: on the same page, there is a Delete All button/link. In Senario 1, we want to know which row to delete after the postback. In Senario 2, if we use asp button and related event handler, generally the process is Page_Load() where databound happens; then OnClick() event handler where to delete; after that we have to redo the databound which cause an extra round trip...