1) When the page is loaded, the operational layers are loaded but no basemap is loaded.
2) When I click the Switch Basemap button and select a basemap, the basemap is loaded but the operational layers become invisible (I guess they are overlaid by the basemap layer.
Now, I want to have a piece of code that
1) the basemap displays in the initial;
2) the operational layers are always above the basemap
3) the basemap's opacity is set below 1 (e.g. 0.7).
Thanks if you can help.