var begin_loading_timer;

if (Sys != null && typeof (Sys) != 'undefined')
    Sys.Application.add_init(appInit);

function appInit(sender) {
    Sys.WebForms.PageRequestManager.getInstance().add_endRequest(endRequestHandler);
    Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(beginRequest);
}

function beginRequest(sender, args) {
    showLoadingOverlay();
}
function endRequestHandler(sender, eventArgs){
    hideLoadingOverlay();
}
function showLoadingOverlay() {
    begin_loading_timer = setTimeout(function() {
        var w = $(document).width();
        var h = $(document).height();
        var offset = $('.shadow1').offset();
        var imgsrc = $('h1 img').attr('src');
        var imgHTML = '<img src="' + imgsrc + '"/>';

        $('#modal_bg').css({
            'width': w,
            'height': h,
            'left': '-' + offset.left + 'px',
            'top': '-' + offset.top + 'px',
            'display': 'block'
        });

        $('#loading_window').css({
            'left': 346 + 'px',
            'top': offset.top + 'px',
            'display': 'block'
        });

        $('p#docIcon').html(imgHTML);
    }, 500);
}
function hideLoadingOverlay() {
    clearTimeout(begin_loading_timer);
    $('#modal_bg').hide();
    $('#loading_window').hide();
}