How do I Import original form

I accidentally purged my orignal form but have a blank copy. 

I've gone onto the website, selected CREATE ONE, then selected Import Form.

There are two selections, From a web page       Clone existing form

I select Clone existing form and the Please Select Window pops up, but I am unable to select.

Thanking you advance.

Have you tried restoring your forms? 

Just click restore then your form can be found in your "My Forms".

Hopefully this can help you, I have accidentally deleted my form before and this method helped me restore it. 

Unfortunately, the Purged forms cannot be restored. 

You do not have any form on your account and because of that, there is no form to be selected. 

I am not sure what do you mean by 'blank copy'. If you have the URL of a form you can import it using Form a Web option- How to Clone an Existing Form from a URL 

If you are unable to import your form, that you will have to recreate it from scratch.

This guides can help you to create a form:

User Guide

How to Create Your First Web Form