Error creating folder

I think I have followed the documentation and I have already read previous posts but it still ain't working for me.

The config file for me is config.php

For the UserFilesPath I tried at first using a format such as

'/mydir/'

and UserFilesAbsolutePath as:

'http://mydomain/mydir/'

But I keep getting an error which says "Error creating folder". So I change the UserFilesPath to my server path:

'/home/myacct/htdocs/mydir/'

but that is throwing an error "Error 1".

Any help please?

Thanks.