QueryString Question

Does this look ok to use? I'm trying to make sure there is nothing in the hidden field and txt boxes prior to making the request fro the querystrings.
I have this in my page load event
If Not Page.IsPostBack Then 'clear all fields here then set them below, just to be sure they start out blank. hfClient_ID.Value = DBNull.Value.ToString hfAccount_ID.Value = DBNull.Value.ToString hfEmail.Value = DBNull.Value.ToString hfEmail.Value = DBNull.Value.ToString txtFirstName.Text = "" txtLastName.Text = "" 'load fields for the Client hfClient_ID.Value = Request.QueryString("Client_ID") hfAccount_ID.Value = Request.QueryString("Account_ID") hfEmail.Value = Request.QueryString("Email") txtEmail.Text = hfEmail.Value txtFirstName.Text ...