HTML file upload: MAX_FILE_SIZE, and/or chunking

Hi,

is it possible to set a max file size for file uploads?

Can such a limit be tested/enforced at client side (ie. in the HTML) before 
the upload starts?

Can such a limit be tested/enforced at server side (ie. in the cgicc 'script') 
before the download starts?

The rationale is b/c the server has only limited ressources, esp. memory.

And a related question:
Is it possible at server side to download the file in multiple chunks, to 
conserve memory?

Thx