svn post-commit question

i have use post-commit by read http://wiki.dreamhost.com/index.php/Subversion

and use Userbased Scripts

but when i update svn by my home PC,it cann't update my homepage hosted dreamhost

if i ./post-commit.bash it's ok

i think the reason is
chown dhapache post-commit
chown dhapache post-commit.bash

but i have not the permissions

how can i do..