How do I use validation plugin for non-standard form submit method?

How do I use validation plugin for non-standard form submit method?

Hi, I'm new to jQuery and the validation plugin, and I'm trying to implement its use for a search form.  When I include a submit button on the form the validation runs fine, but because of design issues we're using an image instead of a submit button and for the href of the anchor tag wrapping the image use "javascript:form.submit();" as the basic format of submitting the form.  In this case the validation isn't running.

Is there some way I can configure the settings for the validator to be able to run even when the form's onsubmit event isn't triggered (which I believe is the case when using this javascript method).  Thanks in advance for any help or advice.