I would like to implement a web form that will display a textbox and submit button that looks up an "account number". When the user types the account number and clicks submit, I want to expand the form to include more controls.

My plan is to create the form with all of the possible controls and set them to visible=False. Then when the user inputs a valid account number, set them to visible=True in the submit button's click event.

My understanding is that the click event fires after the page is posted back but before the HTML is sent to the browser. Is this the best way to code this? Will I be able to set the visible property in the click event, or does it have to be moved to the page's load event? If it has to be moved, how can I examine the button's commandname and commandargument properties in the page load event?