Ubuntu – Cron works, but scheduled job to open webpage in chrome does not

Updates START

1. A friend of mine just answered this. I need to do this export DISPLAY=:0 && <my GUI dependent command here> Waiting for him to post the answer here.
2. I have tried /opt/google/chrome/chrome PARTICULAR_GOOGLE_DOC_URL & without the & too. Still fails. Succeeds directly on command line.
3. There is no /var/log/cron file on my machine. Subsidiary question: How can I get it?

Updates END

I have a Google Doc that I need to update at regular intervals multiple times a day. The content that would form a particular update cannot be predicted or determined programatically. So, the best solution I have is to have the particular Google Doc page open up automatically at fixed intervals and then I manually add the data to it.

Now, the problem is that what works directly on the command line does not work when used in crontab. Below is what I have tried (using 2mins interval just for testing) –

*/2 * * * * date >> /tmp/crontest
*/2 * * * * /opt/google/chrome/chrome PARTICULAR_GOOGLE_DOC_URL &

1. If I cat /tmp/crontest , I see timestamps added there for every 2nd minute
2. If I just try /opt/google/chrome/chrome PARTICULAR_GOOGLE_DOC_URL on the shell, it works as expected
3. But PARTICULAR_GOOGLE_DOC_URL does not get opened in my chrome every 2nd min as it should. (again: I am using 2mins interval just for testing)

What am I doing wrong? How should I fix this? Any alternate way of achieving what I need done?

Thanks in advance.