Question on Frontpage form field validation

In Frontpage 2000, when designing a form, we can have several fields, such as Textbox; and for each field, in form field property, we can set up a validation rule, for example, data value greater than 100. Now I hope to validate the data value of field “p1” equal to data value of field “p2”, how can I do this quickly? This can be used for password confirmation.