function CheckLogin(){
    var d = document.forms("LoginForm"); 
    if(d.UserName.value == ""){alert('用户名不能为空');return false;}
    if(d.Password.value == ""){alert('密码不能为空');return false;}
    return true;
}
function ChgCheckCode()
{document.getElementById('ImgCode').src = '/include/checkcode.aspx?t=' + new Date().getTime()}