Help please

[kriskent]

I've installed ypops, and when i launched it, it says

Last login: Tue Mar 28 13:34:28 on ttyp1
/Users/Kriskent/Desktop/yahoopops_mac_103104/launch_ypops.command; exit
Welcome to Darwin!
KristofferMarlow:~ Kriskent$ /Users/Kriskent/Desktop/yahoopops_mac_103104/launch_ypops.command; exit

------------------------
Hello! This script will launch ypops for you
It runs the command /usr/local/bin/ypops

dyld: Library not loaded: /sw/lib/libxml.1.dylib
Referenced from: /usr/local/bin/ypops.bin
Reason: image not found
done.
Now, you can close this window, or even quit Terminal.app
ypops.bin will still run in the background.
logout
[Process completed]

Why is there an error on my library?

Thanks