Javascript – Client side code will run as/when the controls are rendered on the page. In order for this to work the page has to “load”. As the page is rendering it will fire the code in the order you place them fields vertically and then horizontally (in situations with side by side) on the page. Generally speaking this is all done on the onload event so the controls that the JavaScript is reference are already rendered on the page prior to the JavaScript firing off
Serverside code – SQL controls or plugins will evaluate their code prior to the page loading (on request of page content). Serverside controls, such as the Database Get Control, populate script fields at the database level, therefore, the field value is already "loaded" before the page renders.
Do not use Variables to populate SQL queries, as variables are client side code, there is a small chance that the use of the variable in a SQL query may be blank during its own re-population process.
Server side code also fires in the order they are place on the page (vertical and then horizontal).
With the end call page, the page is never rendered so client side code will not fire. Due the server side code firing on page request before it knows it’s an end call page and trying to render, this means these controls can be placed on the end call page
