/**
 * 触发单击事件
 * @param elem 需要触发事件的DOM对象
 */
function fireClickEvent(elem)
{
    var event;
    if(window.MouseEvent) event = new MouseEvent('click');
    else
    {
        event = document.createEvent('MouseEvents');
        event.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
    }
    elem.dispatchEvent(event);
}


var winX = null;
var winY = null;

window.addEventListener('scroll', function () {
    if (winX !== null && winY !== null) {
        window.scrollTo(winX, winY);
    }
});

function disableWindowScroll() {
    winX = window.scrollX;
    winY = window.scrollY;
}

function enableWindowScroll() {
    winX = null;
    winY = null;
}