Display result in online examsystem

hello there in online exam project when i am dispalying result the condition checking is showing problm it always shows else part
my all coading is below
reply as soon as possible

code for question page

SqlConnection cn = new SqlConnection("Data Source=.;Persist Security Info=False;Initial Catalog=admins;User ID=sa;Password=123456");
    DataSet ds = new DataSet();
   
   
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            cn.Open();
            SqlDataAdapter da = new SqlDataAdapter("select * from ques", cn);
            DataSet ds = new DataSet();
            da.Fill(ds, "ques");
            ViewState["i"] = 0;
            Label2.Text = ds.Tables[0].Rows[0]["quesno"].ToString();
            Label1.Text = ds.Tables[0].Rows[0]["ques"].ToString();
            RadioButton1.Text = ds.Tables[0].Rows[0]["ans1"].ToString();
            RadioButton2.Text = ds.Tables[0].Rows[0]["ans2"].ToString();
            RadioButton3.Text = ds.Tables[0].Rows[0]["ans3"].ToString();
            RadioButton4.Text = ds.Tables[0].Rows[0]["ans4"].ToString();
            cn.Close();
        }


       
    }


   
    protected void RadioButton1_CheckedChanged(object sender, EventArgs e)
    {
        SqlCommand cmd = new SqlCommand("update ques set ans=@ans where quesno=@quesno", cn);
        cn.Open();
        cmd.Parameters.Add(new SqlParameter("@ans", RadioButton1.Text));
        cmd.Parameters.Add(new SqlParameter("@quesno", Label2.Text));
        cmd.ExecuteNonQuery();
       
    }
    protected void RadioButton2_CheckedChanged(object sender, EventArgs e)
    {
        SqlCommand cmd = new SqlCommand("update ques set ans=@ans where quesno=@quesno", cn);
        cn.Open();
        cmd.Parameters.Add(new SqlParameter("@ans", RadioButton2.Text));
        cmd.Parameters.Add(new SqlParameter("@quesno", Label2.Text));
        cmd.ExecuteNonQuery();
    }
    protected void RadioButton3_CheckedChanged(object sender, EventArgs e)
    {
        SqlCommand cmd = new SqlCommand("update ques set ans=@ans where quesno=@quesno", cn);
        cn.Open();
        cmd.Parameters.Add(new SqlParameter("@ans", RadioButton3.Text));
        cmd.Parameters.Add(new SqlParameter("@quesno", Label2.Text));
        cmd.ExecuteNonQuery();
    }
    protected void RadioButton4_CheckedChanged(object sender, EventArgs e)
    {
        SqlCommand cmd = new SqlCommand("update ques set ans=@ans where quesno=@quesno", cn);
        cn.Open();
        cmd.Parameters.Add(new SqlParameter("@ans", RadioButton4.Text));
        cmd.Parameters.Add(new SqlParameter("@quesno", Label2.Text));
        cmd.ExecuteNonQuery();
    }


    protected void Button3_Click(object sender, EventArgs e)
    {
       
        int i = Convert.ToInt32(ViewState["i"]) + 1;
        SqlDataAdapter da = new SqlDataAdapter("select * from ques", cn);
        da.Fill(ds, "ques");
        ViewState["i"] = (int)ViewState["i"] + 1;
        if (ds != null && (int)ViewState["i"] < ds.Tables[0].Rows.Count)
        {
            Label2.Text = ds.Tables[0].Rows[i]["quesno"].ToString();
            Label1.Text = ds.Tables[0].Rows[i]["ques"].ToString();
            RadioButton1.Text = ds.Tables[0].Rows[i]["ans1"].ToString();
            RadioButton2.Text = ds.Tables[0].Rows[i]["ans2"].ToString();
            RadioButton3.Text = ds.Tables[0].Rows[i]["ans3"].ToString();
            RadioButton4.Text = ds.Tables[0].Rows[i]["ans4"].ToString();
        }
        else
        {
            Response.Redirect("result.aspx");
        }


code for result page



 SqlConnection cn = new SqlConnection("Data Source=.; Initial Catalog=admins; User ID=sa; Password=123456");
    DataSet ds = new DataSet();
   
    protected void Page_Load(object sender, EventArgs e)
    {


        cn.Open();
        SqlDataAdapter da = new SqlDataAdapter("select * from ques", cn);
        da.Fill(ds, "ques");
        string a = ds.Tables[0].Rows[0][6].ToString();
        string b = ds.Tables[0].Rows[0][7].ToString();


        if (a == b)
        {
            int m = 1;
            marks.Text = m.ToString();
        }
        else
        {
            marks.Text = "no";
        }
     

database code

create database admins
use admins
create table ques
(
quesno int identity(1,1),
ques char(100),
ans1 char(50),
ans2 char(50),
ans3 char(50),
ans4 char(50),
rans char(50)
)
insert ques values('what is mouse','input device','output device','hard disk','printer','input device')
insert ques values('what is keybord','input device','output device','hard disk','printer','input device')
insert ques values('what is speaker','input device','output device','hard disk','printer','output device')
insert ques values('what is cpu','input device','processing unit','hard disk','printer','processing unit')
insert ques values('what is ram','input device',' temporay storage','hard disk','printer','temporay storage')
insert ques values('what is dam','input/p device',' dtemporay storage','dhard disk','dprinter','dtemporay storage')
insert ques values('what is qram','qinput device',' qtemporay storage','qhard disk','qprinter','qtemporay storage')
insert ques values('what is dam','input/p device',' dtemporay storage','dhard disk','dprinter','dtemporay storage')
insert ques values('what is nam','input/p device',' dtemporay storage','dhard disk','dprinter','dtemporay storage')
insert ques values('what is bam','input/p device',' dtemporay storage','dhard disk','dprinter','dtemporay storage')

alter table ques
add ans char(30)