website - I can't see my web site with www -

i uploaded web site server.

when go http://overflod.mx/, can see page:

but when visit http://www.overflod.mx/ (note: "www" added), can´t see it!

could tell me solve problem? need redirect web site or what?

i think have check cpanel back. have see whether "www" has been added cname on dns. if does, try contacting domain provider.try reading:

wordpress support on www.subdomain.other.com

managing dns records/cname

i hope helps.

all best, muhaimin