The WebMonitor agent evaluated the "Expected Content" as expected. Since the value in the Expected Content field was not found in the page output the page availability was reported as 0.
Use strings found in the "view source" output of the page to populate the "Expected Content" field. You can get the "view source" output for a page by right-clicking on the page and selecting "View source" (IE) or "View Page Source" (Chrome and FireFox).