Dynamically adding CheckBox Controls to TabPages

Question

When I try to Dynamically add CheckBox Controls to TabPages on a tabPage click,
Only one of the four CheckBox is being displayed in the tabPages.

Can anyone help me to make all 4 checkboxes(corresponding to the values:Eastern,Northern,Western and Southern of 'Select RegionDescription from Region') visible and tell what the problem is?!
Here goes the code:

private void tabPage3_Click(object sender, EventArgs e)

{

SqlConnection conn = new SqlConnection("Data Source=DPA1W073B;Initial Catalog=northwind;Integrated Security=SSPI");

SqlCommand cmd = new SqlCommand("Select RegionDescription from Region", conn);

SqlDataAdapter adapter = new SqlDataAdapter(cmd);

DataSet ds = new DataSet();

adapter.Fill(ds);

int CntChkBoxes = ds.Tables[0].Rows.Count;

CheckBox chk;

for (int i = 0; i < CntChkBoxes; i++)

{

chk = new CheckBox();

chk.Text = ds.Tables[0].Rows[i][0].ToString().TrimEnd();

tabPage3.Controls.Add(chk);

}

}