sitemap.xml not writable

[info333]

I am getting these errors any idea what i have done wrong

Warning: file(/home/cottages/public_html/sm/data/sitemap.xml) [function.file]: failed to open stream: No such file or directory in /home/cottages/public_html/sm/pages/class.utils.inc.php(2) : eval()'d code on line 40

Warning: implode() [function.implode]: Bad arguments. in /home/cottages/public_html/sm/pages/class.utils.inc.php(2) : eval()'d code on line 40

[admin]

Hello,

make sure that your sm/data/ folder has 0777 permissions assigned.