window.location.href("./a.htm");//执行后有后退、前进
window.location.replace("./a.htm");//执行后无后退、前进
window.location.replace("./a.htm");//执行后无后退、前进
window.location.href("./a.htm");//执行后有后退、前进
window.location.replace("./a.htm");//执行后无后退、前进
window.location.replace("./a.htm");//执行后无后退、前进