How to access register user wizard elements

<asp:CreateUserWizard runat="server" ID="RegisterUser" ViewStateMode="Disabled" OnCreatedUser="RegisterUser_CreatedUser"><LayoutTemplate><asp:PlaceHolder runat="server" ID="wizardStepPlaceholder" /><asp:PlaceHolder runat="server" ID="navigationPlaceholder" /></LayoutTemplate><WizardSteps><asp:CreateUserWizardStep runat="server" ID="RegisterUserWizardStep"><ContentTemplate><p class="message-info">
Passwords are required to be a minimum of <%: Membership.MinRequiredPasswordLength %> characters in length.</p><p class="validation-summary-errors"><asp:Literal runat="server" ID="ErrorMessage" /></p><fieldset><legend>Registration Form</legend><ol><li><asp:Label ID="Label1" runat="server" AssociatedControlID="Surname">Surname</asp:Label><asp:TextBox runat="server" ID="Surname" /><asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" ControlToValidate="Surname"
CssClass="field-validation-error" ErrorMessage="The Surname field is required." /></li><li><asp:Label ID="Label2" runat="server" AssociatedControlID="Name">Name</asp:Label><asp:TextBox runat="server" ID="Name" /><asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="Name"
CssClass="field-validation-error" ErrorMessage="The Name field is required." /></li><li><asp:Label ID="Label3" runat="server" AssociatedControlID="UserName">User name</asp:Label><asp:TextBox runat="server" ID="UserName" /><asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" ControlToValidate="UserName"
CssClass="field-validation-error" ErrorMessage="The user name field is required." /></li><li><asp:Label ID="Label4" runat="server" AssociatedControlID="Email">Email address</asp:Label><asp:TextBox runat="server" ID="Email" TextMode="Email" /><asp:RequiredFieldValidator ID="RequiredFieldValidator4" runat="server" ControlToValidate="Email"
CssClass="field-validation-error" ErrorMessage="The email address field is required." /></li><li><asp:Label ID="Label5" runat="server" AssociatedControlID="Password">Password</asp:Label><asp:TextBox runat="server" ID="Password" TextMode="Password" /><asp:RequiredFieldValidator ID="RequiredFieldValidator5" runat="server" ControlToValidate="Password"
CssClass="field-validation-error" ErrorMessage="The password field is required." /></li><li><asp:Label ID="Label6" runat="server" AssociatedControlID="ConfirmPassword">Confirm password</asp:Label><asp:TextBox runat="server" ID="ConfirmPassword" TextMode="Password" /><asp:RequiredFieldValidator ID="RequiredFieldValidator6" runat="server" ControlToValidate="ConfirmPassword"
CssClass="field-validation-error" Display="Dynamic" ErrorMessage="The confirm password field is required." /><asp:CompareValidator ID="CompareValidator1" runat="server" ControlToCompare="Password" ControlToValidate="ConfirmPassword"
CssClass="field-validation-error" Display="Dynamic" ErrorMessage="The password and confirmation password do not match." /></li><li><asp:Label ID="Label7" runat="server" AssociatedControlID="Mobile">Mobile</asp:Label><asp:TextBox runat="server" ID="Mobile" /><asp:RequiredFieldValidator ID="RequiredFieldValidator7" runat="server" ControlToValidate="Mobile"
CssClass="field-validation-error" ErrorMessage="The Mobile field is required." /></li></ol><asp:Button runat="server" CommandName="MoveNext" Text="Register" /></fieldset></ContentTemplate><CustomNavigationTemplate /></asp:CreateUserWizardStep></WizardSteps></asp:CreateUserWizard>

this is my asp file 

Debug.WriteLine((TextBox)RegisterUser.WizardSteps[0].FindControl("CreateUserStepContainer").FindControl("Label1"));

and this is what it does not work. How can i acess the various elements of this?