In Page view, double-click a field to edit its properties.
In the Tab order box, type a number (1 - 999) indicating the tab order for the selected field.
If you specify the same number for two or more fields, the field that is first on the page will come first in the tab order. To remove the field from the tab order, type -1.
Repeat this procedure for each field for which you want to set the tab order.
Notes
Only Microsoft Internet Explorer 4.0 and later support a custom tab order. Other Web browsers and previous versions of Internet Explorer use the default tab order.
To test the functionality of your form, you must first publish your web site to a web server running either the FrontPage Server Extensions or SharePoint Team Services from Microsoft. Ask your web server administrator or Internet Service Provider whether this software is installed on your web server. Once the web site is published, click Preview in Browser to test the form.