Dual Boot

I am having HP brio, celeron processor, 128MB sdram. I installed Windows 2000 Professional edition in fat 16 partion. I created 2GB extended partion. In the remain unallocated partion i installed Redhat LInux 7.1. in linux native partion. I am linuxboot disk also. But i am unable to boot linux. Whenever i am switching on the machine it’s booting directly in windows 2000. I installed LILO in first sector of boot partion at the time of linux installation. Through linux boot disk i am able to boot linux. What exactly i want is while the system is booting it should ask to boot any one of the operating system. Please give solution to me.. IT’s very urgent…

regards
sakthi