Get feature info for wms layers

[Nauwanga Nauwanga]

Hello Eeveryone. 

I need help on how to get all individual layers I have loaded to identify. 

Currently, only the first layer I have loaded is showing attribute information. The moment I click on the next layer, it only shows a popup with no attribute.

Kindly refer me to some tutorial codes that can help me resolve this problem.

Many thanks

Amelia