There is some problem with my website. Its page rank was 3. i am not doing any spamming or any kind of work against rules of Google. I did not received any email from Google but one day back page rank of my site is showing 0. Anyone can imagine about my tension, so please help me in detail because i am not well known of developing and java language. .So please help me in easy way. What kind of error is the cause of it and how can I know and remove it.