how to make like the soaptool kit

[lightdoll]

Dear EveryOne...

i want to make some program like soaptool kit because of log.

i used the soaptoolkit to see a soap messages,

if i send lots data to IIS in my program by web service, i should write a
log before sending the data or after, but i make this function in my program,
the program will become slow to send lots data to IIS.
if i don't write a log in my program, it will be find ^^.
so i want to separate the program to write a log.
i need to make a program like soaptoolkit, but i don't have a idea how to
make this kind of program.

Please teach me...