i have been using slackware.i installed open suse 10.1....the grub was installed ...but i wasn't able to boot slackware from grub...there was no option there.... hence i inserted my slackware disk and booted the slackware from my harddisk for installing my lilo....but when i run this as root i get permission denied!!!!1

$/etc/lilo.conf

why is the permission denied for root??

now when i restart lilo is getting loaded instead of grub...
and where did the grub disappear??

/etc/lilo.conf is not an executable program -it's a configuration file.
Perhaps you meant to run the liloconfig program which helps you configure the /etc/lilo.conf file?

If you had slackware installed and then installed SuSE to use grub, then you need to add an entry for Slackware in the grub config file which is being used. You should be able to do this from the running SuSE or by booting using the Slackware install disk. grub doesn't need to be re-written each time you change the config file, so just adding an entry for Slackware and rebooting should work.
Is grub installed to a separate /boot partition or is the /boot directory inside the main SuSE root file system?