root- only user accepted in mysql server

I tried setting up a database server with
RH7.1, apache, mysql, php.

why is it that the only time i can connect to the database server is when I use
@ $db = mysql_pconnect (“localhost”, “root”, “password”);
in the .php files

if i use otherusers such as:
@ $db = mysql_pconnect (“localhost”, “user1”, “password1”);

the browser from both the local and remote machines displays “can’t connect to the database”