you can edit the php files right in html-kit that's one of the big reasons I use it it recognizes php, perl, css, javascript, html, asp and some others.
What you want to do is open dbAcess.php in html-kit then you want to write the code for the dirrefent functions that are currently just stubs in the file
function open() {}//end open
function close() {}//end close
function query($sql) {}//end query
function free_result($resource) {}//end free_result
I already coded num_rows so you can use that for an example. The function you posted above is a correct function but it's not one of them from the dbAccess.php file.
If you want to attempt one and post it here to see if you're doing it right try coding open(). BTW: this should implement two commands and set up the program so that a quers will work you need to use mysql_connect and mysql_select_db for this
here are the manual pages on these functions
http://us2.php.net/mysql_connect
http://us2.php.net/mysql_select_db