WampServer

i am trying to convert a site that works (fairly) well. it is in php4, but it needs to be in php5. The over all idea of the site is to have a calendar where the user can add events, such as birthdays. When i use easyphp to open the site, it works fine, but apparently that is because it uses php4.
When testing my site in wamp, i have the error:

"Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in C:\wamp\www\Copy of 09.01.07\calendrier.php on line 46"

someone told me this is because it is either php5 or mySQL5 that has "a problem" with with the mysql functions....

is there anyone who can explain to me how to sort out my error, and what needs to be changed with the mysql functions to make them work in the version 5?

thank you very much