Loads a local JavaScript file synchronously to your app to make its functionality available in your app.
Example - Compute the Answer to the Ultimate Question of Life, the Universe, and Everything
var scriptJS = `
var num = 7;
function computeNum() { return 6 * num; }
`;
function OnStart() {
app.WriteFile( "script.js", scriptJS )
app.Script( "script.js" );
app.ShowPopup( "script.js loaded." );
app.Alert( computeNum(), "computed number: " );
}