Postback to a gridview on a button click

I've been asked to develop a system to record holiday requests.  I'm completely new to asp.net  so I'm finding it a bit of a struggle.  

At the moment I have a form with two dropdownlists and two text boxes and a button.  The users clicks fills in the form and presses the button and it runs a stored procedure to insert the details into my database.  

What I'm struggling to do or find much information is how to use the information from the controls on the form and populate gridview on the button click.  

Thanks in advance

Dave