[Solved] Why the code does not work?

Question

This line

$link=mysqli_connect('host','username','password','database_name');

should be:

 $link=mysqli_connect($host,$username$,$password,$database_name);

Accepted Answer

This line

$link=mysqli_connect('host','username','password','database_name');

should be:

 $link=mysqli_connect($host,$username$,$password,$database_name);