How to check destination path

[thunder]

my project is an update for our software so I want check the path user selected is correct or not, one special file version.dat exist in target folder,

How can I check version.dat exist or not in user selected path?
if not how to disable next button?

Thanks,
Thunder

[Gaoyuan_Lv]

you can use a rule to check if the file exists.
you can use a custom code to disable the "Next" button.
so i think you can write a custom code and add a rule for it.
if the file does not exist, the custom code should be execute.
for the disable the button, you can see:
http://community.acresso.com/showthread.php?t=187027

[Ranjit_Kumar]

As users provides you the path, save the user specified path in one property and then check in that folder for the files using system search. If that file is not available then abort installation.