Combobox and checkedlistbox

cb = tblEmp
checkedListBox1 = []FName, []LName, []Telephone, []Age, []City

Then if checkedListBox1 =

[x]FName, []LName, []Telephone, [x]Age, [x]City

Datagridview
Philip   21   New York
Charles  25   India
Maciej   24   London
etc

    public partial class Form1: Form
    {
        SqlConnection con = new SqlConnection();
        SqlCommand cmd = new SqlCommand();
        SqlDataReader dr;
        DataTable dt;


        public Form1()
        {
            InitializeComponent();
            Fillcombobox();
            
        }
     
        //Change tbl name on selection isn't working 

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {

       loaddata(comboBox1.SelectedValue.ToString());         
          
        }
        private void Form1_Load(object sender, EventArgs e)
        {
            // Sql Connection if page loads
          }

private void Fillcombobox()
        {
            cmd.CommandText = ("SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES ORDER BY TABLE_NAME ASC");
            con.Open();
            SqlDataAdapter adapter = new SqlDataAdapter(cmd);
            dt = new DataTable();
            adapter.Fill(dt);
            comboBox1.DisplayMember = "TABLE_NAME";
            comboBox1.ValueMember = "TABLE_NAME";
            //Fill combobox with data in DT
            comboBox1.DataSource = dt;
            // Empty bzw. clear the combobox
            comboBox1.SelectedIndex = -1;

            }
        
       
        // A methode to execute a command if page opens
        private void loaddata(string sTableName)
        {
       string CS = (@"Data Source=;Initial Catalog=;Integrated Security=True");
            using (SqlConnection con = new SqlConnection(S))
            {
          con.Open();
cmd.CommandText = String.Format("SELECT [column_name] FROM information_schema.columns WHERE table_name = '{0}'", sTableName);

        SqlCommand command = new SqlCommand(cmd.CommandText, con);
        SqlDataReader reader = command.ExecuteReader();
                if (reader.HasRows)
                {
                    while (reader.Read())
                    {
                        checkedListBox1.Items.Add(reader[0].ToString());
                    }
                }
            }
        }


        /* Display selected options*/
        private void btnShow_Click(object sender, EventArgs e)
        {
            Form2 f2 = new Form2();
            int f = 0;
            string qry = "";
            for (int i = 0; i < checkedListBox1.Items.Count; i++)
            {
                if(checkedListBox1.GetItemChecked(i))
                {
                    if(f == 1)
                    {
                        qry = qry + "," + checkedListBox1.Items[i].ToString();
                    }
                    if (f == 0)
                    {
                        qry = checkedListBox1.Items[i].ToString();
                        f = 1;
                    }
                }
            }
            // A new query to to display the records after checkedbox is clicked
            string newq = "select " + qry + " from tblEmp where [city] = 'Brazil' ";

            // Open form two when btn is clicked
            if (qry != "")
            {
                f2.copyfun(newq);
                f2.Show();
                this.Hide();
            }

            else
            {
                MessageBox.Show("Select an item");
            }

        }

        private void btnZurück_Click(object sender, EventArgs e)
        {
            this.Hide();
            new EinForm().ShowDialog();

        }

    }
}

        public Form2()
        {
            InitializeComponent();
        }

        // Load dgv with a parameter from the query form
        private void loadgrid(string qry)
        {
            string S = ConfigurationManager.ConnectionStrings[""].ConnectionString;
            SqlConnection con = new SqlConnection(S);
            SqlCommand cmd = new SqlCommand();
            cmd.Connection = con;
            cmd.CommandText = (qry);
            DataSet d = new DataSet();
            //DataTable dt = new DataTable();

            SqlDataAdapter da = new SqlDataAdapter(cmd);
            da.Fill(d);
            dataGridView1.DataSource = d.Tables[0];

        }


        public void copyfun(string qry)
        {
            loadgrid(qry);
        }

        private void Form2_Load(object sender, EventArgs e)
        {
            // Sql Connection if page loads
            string S = ConfigurationManager.ConnectionStrings[""].ConnectionString;
            SqlConnection con = new SqlConnection(S);

        }

        private void btnZurück_Click(object sender, EventArgs e)
        {
            this.Hide();
            new Form1().ShowDialog();
        }
    }
}

How do i get the combobox to implement my intention. 
And my sql statement is static instead of making it dynamic.