PHP Registration Page

Hi 

I am fairly new to using PHP and am struggling connecting the MYSQL database to PHP. It will work but when i enter dummy data into the form it won't update within the database. I have already got someone to look over the PHP and they have just given me hints and tips of which I have followed to improve the PHP. 

I just want to be able that when I type in a users data it displays within the MySQL database. 

If someone could help me ASAP that would be great. 

Thanks 

dtferguson