Solution: Make sure that the file you are trying to include() is named correctly, and is pointing to the right path, such as
Warning: main(): Failed opening '/home/the-whom/public_html/layout.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/the-whom/public_html/join.php on line 2
Solution: Check your SQL syntax and make sure that there is indeed a row (or rows) that match the criteria. For example:
Warning: mysql_result()/mysql_fetch_assoc/mysql_num_rows/mysql_fetch_object: supplied argument is not a valid MySQL result resource in /home/the-whom/public_html/join.php on line 78
<?php $sql = mysql_query("SELECT name, id FROM users WHERE name='Jacko'"); //if there is no field called "name" you'll get an error. ?>
Solution: Connect to the Database, and if you have connected, make sure that you have selected which DB you want to use with mysql_select_db().
Error inserting your information into MySQL: No Database Selected
Solution: Make sure the function exists.
Fatal error: Call to undefined function: footer() in /home/the-whom/public_html/join.php on line