mysql database function problem

Hello Everybody! I tried to connect with a mysql databasem , but It shows the follow error: Warning: mysql_numrows(): supplied argument is not a valid MySQL result resource in c:\inetpub\wwwroot\ejercicios\cap11\cursor.php on line 25 Número de filas en el resultado: Warning: mysql_num_fields(): supplied argument is not a valid MySQL result resource in c:\inetpub\wwwroot\ejercicios\cap11\cursor.php on line 29 Warning: mysql_fetch_row(): supplied argument is not a valid MySQL result resource in c:\inetpub\wwwroot\ejercicios\cap11\cursor.php on line 32 Warning: mysql_free_result(): supplied argument is not a valid MySQL result resource in c:\inetpub\wwwroot\ejercicios\cap11\cursor.php on line 40 It seems doesn't recognize the mysql functions I wrote in the code, or did I something wrong? I'm a newbie trying to learn and I have php 4.3.2 with mysql 4.0.13 in a windows xp with ISS 5.0 and I've Installed those programs a lot of times trying to fix it up but the problem remains. I'll really appreciate any help. Andres