jquery: two submit-buttons, but only one should release validation

jquery: two submit-buttons, but only one should release validation

Hello,
I have a form, that uses validation with jquery,
it contains
2 submit-buttons:
one is 'back'
the other is  'forward'

How it should be:
By clicking the 'forward'-submit-button, jquery should validate,
if clicking the 'back'-submit-button, jquery should ignore validation

but the problem is:
jquery validates at each submit

Now my question:
How can I get it,
that there is no Validation, when I click on 'back'-submit-button,
or in other words,
that jquery can differentiate
on whitch submit-button it should validate?

Thanks a lot for your help,
would appreciate if you could help me...