// jQuery plugin to center an element:
// http://plugins.jquery.com/project/autocenter
(function ($) {
    $.fn.extend({
        center: function (options) {
            options = $.extend({ // Default values
                inside: window, // element, center into window
                transition: 0, // millisecond, transition time
                minX: 0, // pixel, minimum left element value
                minY: 0, // pixel, minimum top element value
                vertical: true, // booleen, center vertical
                withScrolling: true, // booleen, take care of element inside scrollTop when minX < 0 and window is small or when window is big 
                horizontal: true // booleen, center horizontal
            }, options);
            return this.each(function () {
                var props = { position: 'absolute' };
                if (options.vertical) {
                    var top = ($(options.inside).height() - $(this).outerHeight()) / 2;
                    if (options.withScrolling) top += $(options.inside).scrollTop() || 0;
                    top = (top > options.minY ? top : options.minY);
                    $.extend(props, { top: top + 'px' });
                }
                if (options.horizontal) {
                    var left = ($(options.inside).width() - $(this).outerWidth()) / 2;
                    if (options.withScrolling) left += $(options.inside).scrollLeft() || 0;
                    left = (left > options.minX ? left : options.minX);
                    $.extend(props, { left: left + 'px' });
                }
                if (options.transition > 0) $(this).animate(props, options.transition);
                else $(this).css(props);
                return $(this);
            });
        }
    });
})(jQuery);

// jQuery plugin to centre popup windows consistently across all browsers
// http://swip.codylindley.com/popupWindowDemo.html
// http://swip.codylindley.com/jquery.popupWindow.js
// Heavily altered, but the principle remains.
function popupWindow(instanceSettings) {
    var defaultSettings = {
        centerBrowser: 0, // center window over browser window? {1 (YES) or 0 (NO)}. overrides top and left
        centerScreen: 0, // center window over entire screen? {1 (YES) or 0 (NO)}. overrides top and left
        height: 500, // sets the height in pixels of the window.
        left: 0, // left position when the window appears.
        location: 0, // determines whether the address bar is displayed {1 (YES) or 0 (NO)}.
        menubar: 0, // determines whether the menu bar is displayed {1 (YES) or 0 (NO)}.
        resizable: 0, // whether the window can be resized {1 (YES) or 0 (NO)}. Can also be overloaded using resizable.
        scrollbars: 0, // determines whether scrollbars appear on the window {1 (YES) or 0 (NO)}.
        status: 0, // whether a status line appears at the bottom of the window {1 (YES) or 0 (NO)}.
        width: 500, // sets the width in pixels of the window.
        windowName: null, // name of window set from the name attribute of the element that invokes the click
        windowURL: null, // url used for the popup
        top: 0, // top position when the window appears.
        toolbar: 0, // determines whether a toolbar (includes the forward and back buttons) is displayed {1 (YES) or 0 (NO)}.
        dependent: false, // adds 'dependent' to the features
        modal: false, // open window modally
        modalArgument: null // an argument to pass to the modal window
    };

    settings = $.extend({}, defaultSettings, instanceSettings || {});

    settings.modal = false;

    var paramSeparator = ',';
    var valueSeparator = '=';

    var AddParam = function (Features, Param, Value) {
        if (Features != '') Features += paramSeparator;
        Features += Param + valueSeparator + Value;
        return Features;
    };
    var windowFeatures = '';
    windowFeatures = AddParam(windowFeatures, (settings.modal ? 'dialogW' : 'w') + 'idth', settings.width + (settings.modal ? 'px' : ''));
    windowFeatures = AddParam(windowFeatures, (settings.modal ? 'dialogH' : 'h') + 'eight', settings.height + (settings.modal ? 'px' : ''));
    if (settings.toolbar && !settings.modal) windowFeatures = AddParam(windowFeatures, 'toolbar', settings.toolbar);
    if (settings.scrollbars) windowFeatures = AddParam(windowFeatures, 'scroll' + (settings.modal ? '' : 'bars'), settings.scrollbars);
    if (settings.status) windowFeatures = AddParam(windowFeatures, 'status', settings.status);
    if (settings.resizable) windowFeatures = AddParam(windowFeatures, 'resizable', settings.resizable);
    if (settings.location && !settings.modal) windowFeatures = AddParam(windowFeatures, 'location', settings.location);
    if (settings.menubar && !settings.modal) windowFeatures = AddParam(windowFeatures, 'menuBar', settings.menubar);
    if (settings.dependent && !settings.modal) windowFeatures = AddParam(windowFeatures, 'dependent', 'yes');

    var openLeft, openTop, win;

    if (settings.centerBrowser) {
        openTop = window.screenY + (((window.outerHeight / 2) - (settings.height / 2)));
        openLeft = window.screenX + (((window.outerWidth / 2) - (settings.width / 2)));

    } else if (settings.centerScreen) {
        openTop = (screen.height - settings.height) / 2;
        openLeft = (screen.width - settings.width) / 2;
    } else {
        openTop = settings.top;
        openLeft = settings.left;
    }
    windowFeatures = AddParam(windowFeatures, (settings.modal ? 'dialogL' : 'l') + 'eft', Math.floor(openLeft) + (settings.modal ? 'px' : ''));
    windowFeatures = AddParam(windowFeatures, (settings.modal ? 'dialogT' : 't') + 'op', Math.floor(openTop) + (settings.modal ? 'px' : ''));

    win = window.open(settings.windowURL, settings.windowName, windowFeatures);
    win.focus();
    return win;
}