Check Member Email, if not null assign to textbox

I trying to do something like this
Dim mb As MembershipUser mb = Membership.GetUser() If mb.Email IsNot Nothing Then txtEmail.Text = mb.Email End If Actually im doing a feedback form that is available for all users
I wan to do if the user is a logged in member, directly assign his name and e-mail to the particular textbox
How should i do that?

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