AJAX ValidationEngine Validation via PHP API Call Script

I am looking to have a validation script written that will automatically validate fields on the fly through AJAX calls primarily to handle an external information validation service we use. We are interested in building upon the ValidationEngine AJAX framework to incorporate this validation. Please see a demo of the desired look and feel of the validation here. It is performing exactly how we want it to: [login to view URL] How it will work from a user perspective: Assume the user is using a generic form that requires an email address, home telephone number, and mobile phone number and a postcode. The user will enter - for example - their email address, and as the field loses focus an AJAX function will kick in which hands the information to the external validation service adhering to their API, which will process the information, and then returns either a success or failure based on the validity of the data, and this is made apparent to the end user via a small graphic, text error message or suchlike as seen in the demo link. This will remove the need for a full form submit and page reload and make the form submission process a hundred times smoother. There are only 3-4 fields that require this external validation (each type of validation is obviously different as it depends on the field contents, and has its own respective call). We require validation of the user’s email address, home telephone number (UK), mobile phone number (UK) and a postcode (UK). The email address is validated by checking against a blacklist of addresses held by the external validation service. We will provide all necessary documents for handling the external validation service API, along with a working example of the API calls in classic ASP which you can use as a reference for coding into PHP/AJAX calls. We ask that the code be well commented to explain the methods used so that future maintenance will be a bit easier. The other fields will also require validation via the ValidationEngine script (name date of birth, dropdown lists etc), which we can script but may pass on to you depending on time restrictions. Also we may build on this script in the future and look to you for the job!