public void Doctor_names()
 {
     Code cd = new Code();
     DataSet ds = cd.Assign_Doctorslist_Dropdown();
     if (ds != null && ds.Tables[0].Rows.Count > 0)
     {
         DropDownList1.DataTextField = "Name";
         DropDownList1.DataValueField = "ID";
         DropDownList1.DataSource = ds;
         DropDownList1.DataBind();
         DropDownList1.Items.Insert(0, " ");
     }
 }