I am not able to include
http://maps.googleapis.com/maps/api/js?sensor=false. Whenever I load my portlet for the first time it doesn't work but if I refresh the same page then it starts working fine. I don't know what the issue is. Please Help.
One of the clean ways to include js file in a portlet, independent of the portal server is to configure in portlet deployment descriptor file as below. For liferay, it would be liferay-portlet.xml.
What do you mean by "it doesn't work"? Where did you put it. Inside portlet's jsp? Could you share code so we can see what you are doing.
Nevertheless this should work