Pycharm install - JDK
===

I try to install pycharm on Ubuntu 12.04 and I have this information:

    user@user:~/Pobrane/pycharm-2.5.2/bin$ sh pycharm.sh
    OpenJDK Runtime Environment (IcedTea6 1.11.1) (6b24-1.11.1-4ubuntu3)
    OpenJDK Server VM (build 20.0-b12, mixed mode)
    WARNING: You are launching the IDE using OpenJDK Java runtime.
    
             ITS KNOWN TO HAVE PERFORMANCE AND GRAPHICS ISSUES!
             SWITCH TO THE ORACLE(SUN) JDK BEFORE REPORTING PROBLEMS!
    
    NOTE:    If you have both Oracle (Sun) JDK and OpenJDK installed
             please validate either PYCHARM_JDK, JDK_HOME, or JAVA_HOME environment variable points to valid Oracle (Sun) JDK installation.
             See http://ow.ly/6TuKQ for more info on switching default JDK.
    
    Press Enter to continue.


What to do to work normally?