Oracle 11g installer - error "DISPLAY not set" (SuSE Enterprise 10 SP3)

Good evening to all! :-) Need some help from experinced Oracle users. I am trying to install Oracle 11g to SuSE Enterprise Server 10 SP3 (x86). I checked all necessary RPM's - looks like all is OK. Then I am typing:
sudo -u oracle ./runInstaller
But installer answered me:

Could not execute auto check for display colors using command /usr/X11R6/bin/xdpyinfo. Check if the DISPLAY variable is set. Failed <<<<

Some requirement checks failed. You must fulfill these requirements before continuing with the installation,
Continue? (y/n) [n]

Well, I pressed "y" - installer answered:

Ignoring required pre-requisite failures. Continuing...

Preparing to launch Oracle Universal Installer from /tmp/OraInstall2012-03-11_11-06-54PM. Please wait ...
DISPLAY not set. Please set the DISPLAY and try again.
Depending on the Unix Shell, you can use one of the following commands as examples to set the DISPLAY environment variable:
- For csh: % setenv DISPLAY 192.168.1.128:0.0
- For sh, ksh and bash: $ DISPLAY=192.168.1.128:0.0; export DISPLAY
Use the following command to see what shell is being used:
echo $SHELL
Use the following command to view the current DISPLAY environment variable setting:
echo $DISPLAY
- Make sure that client users are authorized to connect to the X Server.
To enable client users to access the X Server, open an xterm, dtterm or xconsole as the user that started the session and type the following command:
% xhost +
To test that the DISPLAY environment variable is set correctly, run a X11 based program that comes with the native operating system such as 'xclock':
% <full path to xclock.. see below>
If you are not able to run xclock successfully, please refer to your PC-X Server or OS vendor for further assistance.
Typical path for xclock: /usr/X11R6/bin/xclock

Then I checked DISPLAY variable:
echo $DISPLAY
127.0.0.1:1.0
Should I change this variable? Thanks for support :-)