Random rnd = new Random();
int pause = rnd.Next(3, 5);
HtmlElement he = instance.ActiveTab.FindElementByAttribute("div", "class", "m-block", "regexp", 0);
if (he.IsVoid) throw new Exception("Не нашли элемент");
instance.ActiveTab.FullEmulationMouseMoveToHtmlElement(he);
instance.ActiveTab.FullEmulationMouseClick("left", "down");
for (var i=0;i < pause;i++){
Thread.Sleep(1000);
}
instance.ActiveTab.FullEmulationMouseClick("left", "up");