Mouse Click marker to display infowindow in placeholder on ‘MouseClick’ Event.To show infowindow you should do following steps :
Step 1Go to Add or Edit Map and scroll down to ‘Infowindow Settings’ section.
Step 2Point to ‘Show Infowindow on’ option and select ‘Mouse Click’ from drop down list.
Step 3Save the map and open it in a browser.

Video Tutorial