Output data-gathering ScriptUI window

var outputData = new Window("dialog", windowTitle);
    outputData.orientation = "stack";
    outputData.margins = 0;
    var bgImagePrefix = artDeptFolderPrefix + "Product Templates/references/";
    var bgImage = outputData.add("image", undefined, File(bgImagePrefix + "Job_Output_3.00.jpg"));
    var stackGroup = outputData.add("group");
        stackGroup.margins = [0, 48, 0, 0];
        stackGroup.alignment = ["", "top"];
        stackGroup.alignChildren = ["", "top"];
        var textPanel = stackGroup.add("panel");
            textPanel.orientation = "row";
            textPanel.alignChildren = ["", "bottom"];
            var staticGroup = textPanel.add("group");
                staticGroup.orientation = "column";
                staticGroup.alignChildren = "right";
                staticGroup.spacing = 16;
                staticGroup.graphics.foregroundColor = staticGroup.graphics.newPen(outputData.graphics.PenType.SOLID_COLOR, [1, 1, 1], 1);
                staticGroup.add("statictext", undefined, "&Order Number:");
                staticGroup.add("statictext", undefined, "&Ship Date:");
                staticGroup.add("statictext", undefined, "&Initials:");
                staticGroup.add("statictext", undefined, "Ove&rruns?");
            var editGroup = textPanel.add("group");
                editGroup.orientation = "column";
                editGroup.alignChildren = "left";
                var orderNumText = editGroup.add("edittext");
                    orderNumText.characters = 8;
                    orderNumText.active = true;
                    orderNumText.onChange = function ()
                    {
                        if (!/\b\d{6}\b/.test(orderNumText.text) && !/\bP\d{5}\b/i.test(orderNumText.text) && orderNumText.text != "")
                        {
                            // If the entered text does not contain exactly 6 digits.
                            alert("The order number does not appear to conform to a standard order number.\n Please fix and try again.");
                        }
                        okButton.enabled = ifFieldsFilled();
                    }
                var shipDateText = editGroup.add("edittext");
                    shipDateText.characters = 8;
                    shipDateText.onChange = function ()
                    {
                        dateValid = isDateValid();
                        okButton.enabled = ifFieldsFilled();
                    }
                var initialsText = editGroup.add("edittext");
                    initialsText.characters = 3;
                    initialsText.onChanging = function ()
                    {
                        okButton.enabled = ifFieldsFilled();
                    }
                    initialsText.onChange = function ()
                    {
                        okButton.enabled = ifFieldsFilled();
                    }
                var overRunsBox = editGroup.add("checkbox");
        var buttonGroup = stackGroup.add("group");
            buttonGroup.orientation = "column";
            var okButton = buttonGroup.add("button", undefined, "OK", {name: "ok"});
                okButton.enabled = ifFieldsFilled();
            var cancelButton = buttonGroup.add("button", undefined, "Cancel", {name: "cancel"});