Bootstrap Form - Validation Error Alert

have 3 bootstrap forms that have various mandatory data fields. I'm using the validating routine that's a part of bootstrap v3 All works a-ok on the forms. Fields validate etc BUT Since these forms are fairly long in length, when someone forgets to fill in some fields and hits the "Submit Button" the submit button becomes "disabled/inactive" until the fields up above get filled in properly, which is expected On an iphone especially the person filling in the phone can't seem to grasp that form fields above need their attention.. I want to place an "Alert" above/below" the submit button (like in the sample image attached) so that if their are form fields that are mandatory and still need to be filled, it's really clear there is a problem up above. Once the fields that are mandatory have their data input this "alert" would then disappear and the form can be submitted..... I need someone to write some code that I can then place into my 3 forms to achieve this. I can send along the sample form html which will show you how the form is acting currently etc. I suspect some of out bootstrap css files will be out of sync, I see no reason to send you all of the files I have in use, just the form..... This doesn't seem like it should all that difficult, calling an alert (like in my sample image) in bootstrap if a form fails, but it seems to be over my head code-wise for some reason. Time for a helping hand! I can send along the form html file when needed.....