How to install dual operating systems like windows vista home basic &win xp

Hi Guys

I buy new laptop in that windows vista home basic os is there. i want to make a dual operating system to install win xp. i am poor in installation part. kindly give me suggestions.

Note: i make NTFS partion for new win xp os
when i am trying to install win xp in that partion from cd it will give the error.

thanks and regards
srihari