function Position(_window, id) {

    this.Dimension = new Dimension(_window);
    this.Dialog = function() {
        var clientWidth = this.Dimension.GetClientWidth();
        var clientHeight = this.Dimension.GetClientHeight();

        var scrollX = this.Dimension.GetScrollXY()[0];
        var scrollY = this.Dimension.GetScrollXY()[1];

        var width = this.Dimension.GetElementWidth(id);
        var height = this.Dimension.GetElementHeight(id);
        var left = (clientWidth - width) / 2;
        var top = (clientHeight - height) / 2;

        left += scrollX;
        top += scrollY;

        var divDlg = _window.document.getElementById(id);
        divDlg.style.left = left + 'px';
        divDlg.style.top = top + 'px';
    }
}