reset password

Hello,
I'm trying to retrieve or reset a password.
protected void Page_Load(object sender, EventArgs e)

    {
        string username = "xxxxxxxx";
        string password = "xxxxxxxx";
        MembershipUser mu = Membership.GetUser(username);
        mu.ChangePassword(mu.ResetPassword(), password);
      
    }
 I got an error that I was unable to reset passwords.
All the data in the tables is hashed. In the web.config there is no mention of a SQL Membership Provider.
any ideas how I can change/reset the password?
 
thanks.
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