how to disable CompleteWizardStep in CreateUserWizard

Hi All,
I have created CreateUserWizard and working fine. But I want to show successful message after creation, i used
ScriptManager.RegisterStartupScript(this, GetType(), "myalert", "alert('" + msg + "');window.location(news.aspx);", true);
to show pop up. But Account is created successful and it logged out current user and logged in as new created user.
i already added DisableCreatedUser="true". But it shown complete wizard step and when i clicked on next, current user logged out and new created user logged in.

please advice, need to show pop up successful message without logging out from current user.

thanks