Website cant connect to other site? (mysql question)

Can you connect a Website on a Host to a mysql database from a database?? i am trying to use a register form and it doesnt work when its on my host, but when i use that register form on my PC it works (the database is hosted on my pc)

Yes you can remotely connect to a database- IF YOUR HOST ALLOWS IT.  otherwise you're SOL.  My host is netfimirms they give me the option to allow remote connections.  Of course, when you connect remotely the name 'LocalHost' will no longer be enough, you will require the name of the databse you are connecting to and it's IP.  ask your hosting company for these things.