>Yes, I thought about it... So, DynaZip itself should have a mechanism to check. Basically, this kind of error is rare, may be that's why they didn't put additional efforts into it...

There are just some things the user should be responsible for. Following screen prompts and instructions to do something should be one of those. This is one of the problems with computers, we [users] are getting more lazy and are expecting the computer to catch and correct all our mistakes.