Simple API retrive, display and input Call JavasScript/PHP

Write a JavaScript program that will retrieve XML data from another server and post the information to the Web page. The data will be received from the database using PHP. Submit data such as name, address and package it up into XML and call the API and input it into the database. The page that it will connect to will be PHP and enter the data into MySQL. XML format will be provided. This is an attempt to understand the programming logic of building an API. Nothing fancy about the project. You have to create the PHP file, retreive the data and format it into the XML format we send you. It will display the XML while calling the PHP file in the browser. You will than create a HTML file that has Javascript and call the PHP file and retreive the XML. You will than populate the data from the XML and input it into a text field box. You will submit the information in the text field box and format the data from the text field box, format it into XML using Javascript and connect to the PHP file to send the XML data (DOM) as an API call. The PHP file will take the data and enter the information into the database. We will be able to see if the data was updated when the page returns displaying the updated data in the field box.