Passing username value from Login to default

Question

Hello,

I'm using forms authentication with active directory.

if (domainProvider.ValidateUser(txtUsername.Text, txtPassword.Text))
{
FormsAuthentication.RedirectFromLoginPage(txtUsername.Text, false);
}

How can I pass the value from txtUsername.Text to default.aspx so I can use it to query a SQL server database for the first name/last name etc.
Thank you!