crontab -e problem for new user in solaris

I found that the "crontab -e" command cannot work for the newly created user "datadm".
It prints "0" and "?", then seems hanging there without ending. It turns out to be the problem of default editor setting. Set it to "vi" will solve this problem. Now, put the following lines input your .profile if you are using "sh".

EDITOR=vi
export EDITOR

That's all. You can now use "crontal -e" to create scheduled tasks.