function login() {
    var username =encodeURI(document.getElementById("username").value);
    var pwd =encodeURI(document.getElementById("pwd").value);
    var validator=document.getElementById("validator");
    var cok = getCookie("yzmcode");
    if (username != null && pwd != null && validator != null&&username != "" && pwd != "" && validator != "") {
        if (cok.toLocaleLowerCase() == (document.getElementById("validator").value).toLocaleLowerCase()) {
            location.href("/Helper/shvelogin.aspx?username=" + username + "&pwd=" + pwd);
        }
        else {
            alert('您输入的验证码不正确!');
        }
    }
    else
    {
    alert('请输入用户名和密码');
    }

}