Do not move to next step if Form is not Valid

Hello,

We have a guide which leads the user through a slide out form with required fields.  When the user presses save, a javascript validation method is initiated and, if the form is valid, the slide out hides itself.  Only then do we want to go to the next (and final) step which congratulates the user on the completion of the workflow.  Currently, the last step is being displayed even if validation messages occur.  Is there anyway to verify that there are no validation messages at the top of the page prior to moving to the final step of the guide?

We thought about changing the slide out to disable the button until the form is 100% valid, but not sure we want to change functionality for the guide.  Is there any other way to do this?

Thank you,

Andrew