binding data from DB to Gridview

//postback for button event in page load
btnSaveClose.OnClientClick = String.Format("fnClickSave('{0}','{1}')", btnSaveClose.UniqueID, "");

//sample data bind from DB to checkbox
SqlConnection
string myquery = "select Qualification from tblQualificationLookup";
SqlCommand mycmd = new SqlCommand(myquery);
string mycmd.Connection = conn;
dt = ad.Fill(dt);
chkQualification.DataSource = dt;
chkQualification.DataTextField = "Qualification";chkQualification.DataValueField = "Qualification";chkQualification.DataBind();
conn = new SqlConnection(myConnectionString);