Writing a proof of funds letter for visitor

[Pamcalgary]

Hi All,
I have to write a letter for my boyfriends application to extend his visitors visa. We want him to stay until I save enough to go back with him to the U.S for a couple of months while he works.
I have to write a letter stating that I will be providing him with money while he is visiting. Does anyone know where I can get information about this letter to make sure I write it properly?
Thank you,

 

[Suin]

Check these three links:

http://www.cic.gc.ca/english/visit/letter.asp

http://2013.colloquium.cochrane.org/sites/2013.colloquium.cochrane.org/files/Visas_required%20documents.pdf

http://www.studyvec.com/seattle-visa-trip/page11.html

In stead of "parents", use "my friend". The idea is the same.