Is this UML sequence diagram of a AJAX - database query with JS and PHP right?

Question

I have the following UML diagram of a web application. It is a web-based analysis tool, where the user can perform requests in a GUI to gain some values from a DB. The values are loaded via AJAX-requests.

First, the user clicks a button to perform a jQuery-based request of a KPI-value. The webserver with PHP performs an sql query on a sqlite database and then the GUI updates a diagram in the browser.

Is this diagram correct?

Answer 1

Is just 'yes' an acceptable answer on SO? If not I would say: 'Yes the diagram is ok' :)