When I update the data into the field of dropdownlist, I get error as 
DropDownList' has a SelectedValue which is invalid because it does not exist in.
here is the code:-
public void FunFillDetails() { string ObjProMkey = TxtMKey.Value; DataAccessLayer ObjProdat2 = new DataAccessLayer(Providers.ConfigDefined); //DbDataReader ObjProDr = ObjProdat2.ExecuteReader("select isnull(SubDept_mkey,0) as SubDept_mkey1,* from emp_mst where mkey =" + ObjProMkey); DbDataReader ObjProDr = ObjProdat2.ExecuteReader("Select isnull(mkey,0) as Mkey,* from p_emp_mst_self where mkey=" + ObjProMkey); while (ObjProDr.Read()) { strPubMkey = ObjProDr["mkey"].ToString(); ddlTitle.SelectedValue = ObjProDr["title"].ToString(); txtTitle.Text = ObjProDr["title_other"].ToString(); ...

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