ASP.NET

//Form2


        public void dataGridView1_CellContentClick(object sender, DataGridViewCellEventArgs e)
        {
            sample(this,e); 
        }

        public int sample(object sender, DataGridViewCellEventArgs e)
        {
            currentRow = e.RowIndex;

            try
            {
                IdString = dataGridView1[0, currentRow].Value.ToString();
                
                nextrow = dataGridView1[0, currentRow + 1].Value.ToString());
                
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            if (dataGridView1.Columns[e.ColumnIndex] == editButton && currentRow >= 0)
            {
                string FileName = dataGridView1[1, currentRow].Value.ToString();
                string Fileno = dataGridView1[2, currentRow].Value.ToString();
                string Filetype = dataGridView1[3, currentRow].Value.ToString();
                string Address = dataGridView1[4, currentRow].Value.ToString();
                //this.Hide(); 
                Form3 f3 = new Form3(IdString, nextrow);
                f3.Show();
            }
               return nextrow;
         }
}

//Form3

        public void button3_Click(object sender, EventArgs e)
        {            
           exam(this, e);  //am getting error here. so wat parameter i need to pass since for button click event i cant add DataGridViewCellEventArgs               
        }

        public void exam(object sender, DataGridViewCellEventArgs e)
        {
            Form2 frm2 = new Form2();
            test1 = frm2.sample(this, e);
            myConnection = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:\\DFMS\\DFMS.mdb");
            myConnection.Open();

            string query = "select SlNo, FileName, Fileno, Fileloc, Filetype, Address, Surveyno, A, G, Sqmt, Resdate, Issueddate, Remarks from SRCH where (id = " + test1 + ")";
            OleDbCommand cmd = new OleDbCommand(query, myConnection);
            OleDbDataReader dr = cmd.ExecuteReader();

            while (dr.Read())
            {
                label26.Text = dr["SlNo"].ToString();
                label24.Text = dr["FileName"].ToString();
                label23.Text = dr["Fileno"].ToString();
                label22.Text = dr["Fileloc"].ToString();
                label21.Text = dr["Filetype"].ToString();
                label20.Text = dr["Address"].ToString();
                label19.Text = dr["Surveyno"].ToString();
                label18.Text = dr["A"].ToString();
                label17.Text = dr["G"].ToString();
                label16.Text = dr["Sqmt"].ToString();
                label15.Text = dr["Resdate"].ToString();
                label14.Text = dr["Issueddate"].ToString();
                label13.Text = dr["Remarks"].ToString();
            }
            myConnection.Close();
            test1 = test1 + 1;
        }
    }
}

Could not load type 'HelloWorld._Default'.