File upload & chmod security question

I have an upload sytem in place so users can share there works. Problem is I can only get the upload to work if the directory is set to 777. I understand this can be a security issue and that most directories shold be set to 755. Is there a safe way of doing this? I tried to use PHP’s chmod function to chmod the directory to 777 for upload and back to 755 when the upload was complete but I kept getting a permissions error.

example:
Warning: chmod() [function.chmod]: Operation not permitted in yada yada yada.

I assume this is because my shared host doesn’t allow it? Tried searching for an answer but I came up with nothing helpful. Any ideas would be appreciated.

Thanks.

edit: I just realized I posted this in the Javascript forum :p sorry bout that… hopefully an admin can move it shortly.

Also in #JavaScript _↴