newbie and a link index error

hello, what does this error indicate and how do I correct it. I am attempting to read a single form field from a php script into a mysql database

Warning: 0 is not a MySQL link index in /test_homework.php3 on line 27

thank you in advance
DW

You are passing a link index that doesn't exist. The link index is obtained when a mysql_connect() or mysql_pconnect() is called. e.g.:

$linkid=mysql_connect('host','user','password');

Some mysql functions allow you to include the link index as an argument, although usually it is not required as PHP will use the currently open connection.

HTH