Being a bit lazy, and absent from php a while (rusted) I downloaded and implemented this php database class. Works sweet.

However, this oke use mysql in the class, and I considered changing to mysqli
MySQLi is an improved database layer for PHP 5 and MySQL 4.1+. It is strongly recommended that MySQLi be used if your MySQL server is at version 4.1 or higher !
Just wonder, would it work if I swap out all the mysql calls with their mysqli equivalents?
I remember vaguely (or imagining myself) that's not the case, and guess I need to do some research. Just have limited time, so figured drop a Q here.
mysql_connect
mysql_select_db
mysql_query
mysql_num_rows
mysql_fetch_row
mysql_data_seek
mysql_insert_id
mysql_close