Can anyone help?

Im creating a website where i need users to log in to use the features the website provides.

 

However im having a little trouble making it so that people can register using a password and username.

 

i can make it so that people fill-in feedback forms but i cant make it so that they actually need a password and the like to login automatically.

 

Can you help me?

 

Do you know the html code im looking for?

 

Cheers