Auto-increment mark Problems

Questions about auto-increment identity: Delphi/Windows SDK/API
Http://www.delphi2007.net/DelphiBase/html/delphi_20061207141109242.html
I made a registry, with ID as the identifier, each auto-increment. during registration, I need to enter the password and user name. when running the command, the system prompts that the "ID" must be assigned... how can I solve this problem... thank you for your advice.

Code As follows:
Begin
Userload. append;
Userload. Fields [3]. asinteger: = right;
Userload. Fields [1]. asstring: = edit1.text;
If (edit2.text = edit3.text) then
Begin
Userload. Fields [2]. asstring: = edit3.text;
End
Else
Begin
Application. MessageBox ('the password is inconsistent. Please enter it again! ', 'Records not found', mb_ OK );
Edit2.text: = '';
Edit3.text: = '';
End;
Userload. post;
Userload. Refresh;

Userload. Fields [0] In the table is ID

Let's take a look...

How can I deal with the auto-increment Id set in my table !? Assign a value to it when adding it, prompting that the display value cannot be added. If no operation is performed, the ID must have a value? What should I do?

This value should be automatically added by the system. How can I ask you to operate it ??