Javascript Form Validator UK Postcode Validator

We are a small finance company and take online applications for finance which consists of a html form which uses asp to submit data entered into a Microsoft Access database.

We will require you to create basic javascript validation eg. empty fields, incorrect email address format ect.

We will also require some sort of UK postcode script similar to the one here; https://www.yesloansuk.com/apply.php We will require the user to enter a postcode and the address to come up.