Auto populate fields based on user selected crm integration drop-down list

Auto populate fields based on user selected crm integration drop-down list

I have an app that I am trying to update customer details in a form based on an integration drop-down. I would like to select a customer in the crm integration drop-down list and then based on the selected record it updates customer values on the form; name, phone, email, and address. 

I have tried a few deluge scripts but I am unable to get it to link the data from CRM. Any help would be greatly appreciated.