persistent data

//app.bringToFront();

var settings = new File(app.preferencesFolder + "/{06704d4d-4e32-4c26-87ab-78d674f1eeab}.dat")
var myInstagram; if (myInstagram == undefined) myInstagram = "instagram name here";
try { if (settings.exists) $.evalFile(settings); } catch(e) { alert(e); }

if (!documents.length) {
    alert('There are no documents open.', 'No Document');
}

else {
    main();
}

function main() 
    {
    try {
        //  Ask user for input by showing prompt box and save inputted value to variable:

        var win = new Window('dialog','Text Input');
        win.orientation='column';   
        win.alignChildren = 'left';
    
        var grp3 = win.add ('group');   
        var pnl7 = grp3.add('panel',undefined,'Instagram', {borderStyle: 'black'} );
        pnl7.orientation='row';
        pnl7.alignChildren = 'left';
        var instaCB = pnl7.add('checkbox',[10,10,40,20],'On');
        var instagramDetail = pnl7.add('edittext', [50,10,220,20], myInstagram);
    
        var grp2 = win.add ('group');
        var b1 = win.add("button",  undefined, "OK");
        b1.preferredSize = [70,20];

        b1.onClick = function ()  
            {    
            try {
                myInstagram = instagramDetail.text;   

                save_settings();  

                win.close()    
                }
            catch (e) { alert(e); }        
            } 
    
        var myReturn = win.show();
        }
    catch (e) { alert(e); }        
    }

function save_settings()  
    {  
    try {
        settings.open("w");  

        settings.writeln("var myInstagram = " + myInstagram.toSource())  

        settings.close();  
        }
    catch (e) { alert(e); }        
    }