In .Net I Have Fields(Name,Dob,Marital Status) I Have A Dropdownlist With 3 Contents(Select,Married.Unmarried).After Saving Everytime The Saved Option Replicates Any Other Option.I Have Refresh...

protected void btnadd_Click(object sender, EventArgs e)
       {
{
 SqlCommand cmd = new SqlCommand ("insert into personalinformation(name,dob,maritalstatus,)
 values('" + txtname.Text + "','" + txtdob.Text + "','" + ddlmaritalstatus.SelectedItem.Text + "'", conn);

conn.Open();
cmd.ExecuteNonQuery();
conn.Close();
refresh();
ShowMessage("Added Successfully");
            }

private void refresh()
       {
           txtdob.Text = "";
           txtname.Text = "";
        
           ddlmaritalstatus.selectedItem.Text="Select";
           
           gridviewload();
       }