title: What is the reason if Roles.AddUserToRole(..) does not work?
body: <p>I implemented membership in asp.net, I have a manager that can define users, users have USER role, when I use below code to assign role, it does not work:</p>
  
  <pre><code>Roles.AddUserToRole(txtUsername.Text, "USER");
  </code></pre>
  
  <p>Now my question is: 
  What is the reasons?</p>
  
  <p>when I log in and check its roles, there is no role. I use this code for detect role:</p>
  
  <pre><code>string[] role = Roles.GetRolesForUser(txtUserName.Text);
  </code></pre>