Adding user with Sudo permission in solaris 9

How can I add user with Sudo permission in solaris 9 ? I'm new in Solaris

There is no sudo by default in Solaris 9. Also is a question like this really easy to answer by using a searchengine...

unix - Where is the sudoers file on Solaris? - Server Fault

You can get source and binaries for Solaris 9 from here. After installing you will find /usr/local/etc/sudoers and /usr/local/bin/sudo