Hey guys I am making a website and I have 2 contact forms on the page, one is not functional and the other has been coded and has the .php script to allow the form to function BUT every time i click the submit button i get this error;

File "/websites/123reg/LinuxPackage23/ha/rd/ka/hardkase.co.uk/public_html/contactform.php" is writeable by others.

how do i fix this, i dont have much knowledge on php?

the web page in question is www.hardkase.co.uk/contact.html