Made secondary dir list more intuitive when primary sort field empty

Form1.cs

@@ -158,6 +158,13 @@ namespace photo_sorter
                         lbox_secondary_sortlist.Items.Add(dir);
                     }
                 }
+                lbox_secondary_sortlist.Enabled = true;
+            }
+            else
+            {
+                lbox_secondary_sortlist.Items.Clear();
+                lbox_secondary_sortlist.Items.Add("-- Select Primary Sort --");
+                lbox_secondary_sortlist.Enabled = false;
             }
         }
 
@@ -640,12 +647,12 @@ namespace photo_sorter
         }
         private void cbox_sort_secondary_Enter(object sender, EventArgs e)
         {
-            if (cbox_sort_primary.Text.Length > 0)
-            {
+            //if (cbox_sort_primary.Text.Length > 0)
+            //{
                 populate_directory_lists();
                 tabctrl_sort_dir.SelectedTab = tabctrl_sort_dir.TabPages["tab_secondsort"];
                 cbox_sort_secondary.Focus();
-            }
+            //}
         }
         private void lbox_primary_sortlist_SelectItem(object sender, EventArgs e)
         {