Click Start > Configuration > Email & Integration > Web Integration > New Lead Key or New Case Key.

Select a user or queue using the dropdown picklist next to Queue to assign to.  This determines who any Leads or Cases submitted using this form are assigned to.

Select a user name from the dropdown picklist next to Created by.  This is the user in whose name the Case or Lead will be created.

NOTE:  If you delete or disable a user who has been used in a Web Key as the creator of a record, the records will no longer be generated.  In this circumstance, you should edit the Web Key and recreate the web form.

Click Save & Close.  The new key will now appear in the grid on the right.  Click on the key to open it and click on Form.  This will download an HTML form that can be used in your website.