E-commers project

Question

hi frnds,

i am working on ecommers project and working on purchase module..

now i want if i purchase the items and if i cancel the order ,,how to do it??

example - after gave the ordered it is saved..

2. i gave fine button there so i find that order is generated..

now i want to ,if i cancel that order so how to comup with idea in asp.net???