Determine if the website at http://agrar.hu-berlin.de/ is currently accessible. If it is inaccessible, clearly state the specific error message encountered when attempting to load the page. Do not attempt to navigate further if an error occurs.
Attempt to navigate to http://agrar.hu-berlin.de/ If navigation fails, identify and record the specific error message displayed.
Successfully attempt to navigate to http://agrar.hu-berlin.de/. Correctly identify that the website is inaccessible. State the exact error message encountered: 'net::ERR_NAME_NOT_RESOLVED'.