function requestContent(item){
	$.ajax({
		url: item + '.html',
		cache: false,
		success: function(data) {
			$("#mainContent").html(data);
			
			// google+ request
			var usrId = '105670859199089822415';
			var appKey = 'AIzaSyBZ4FyfQjrRUiPXcnAYXfzcYxS2VYBNOl4';
			var maxResults = 0;
			
			switch(item){
				case 'home':
					// request google+ activities
					requestGPlusActivities(appKey,usrId,maxResults);
					break;
				case 'about':
					// request google+ profile
					requestGPlusProfile(appKey,usrId);
					break;	
				case 'photos':
					// request picasa albums
					requestPicasaAlbums(usrId);
					break;
			}
		}
	});
};