function Check() {

    var VName = document.MemberLogin.LoginName.value;
    if (checkspace(VName) || VName.length < 3|| VName.length > 20) {
        alert("Please enter the correct user name!"); //请输入正确的用户名！
        document.MemberLogin.LoginName.focus();
        return;
    }


    var VPwd = document.MemberLogin.LoginPwd.value;
    if (checkspace(VPwd) || VPwd.length < 6 || VPwd.length > 20) {
        alert("Please enter the correct password!"); //请输入正确的密码!
        document.MemberLogin.LoginPwd.focus();
        return;
    }
    document.MemberLogin.submit();
}

function checkspace(checkstr) {
    var str = '';
    for (i = 0; i < checkstr.length; i++) {
        str = str + ' ';
    }
    return (str == checkstr);
}