"not a valid MySQL Result Resource"

[Mr__Feces]

I am trying too learn PHP, and I made a simple script. However, when I try to use the code

while($row = mysql_fetch_array($result))

to show a list of rows in a certain column of a table, I get this warning:

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /path/to/script.php on line 16

[laserlight]

1. Check your database server connection.
2. Check that a valid database has been selected.
3. Check that the SQL statement is correct, and that $result is a valid result resource.

[Mr__Feces]

I don't think #1 or #2 is the problem, because I have connected to the MySQL database in the same script to use the INSERT INTO command.
Here is the $result variable. I used a tutorial.

$result = mysql_query("SELECT * FROM a_table");

[Mr__Feces]

OK, I fixed that error (typo in the SQL command) but it brought about more errors.
I have this line 2 lines down from that

echo $row['some_row'];

and I get this error: Parse error: parse error, expecting T_STRING' orT_VARIABLE' or `T_NUM_STRING' in /path/to/script.php on line 17

[thorpe]

Where going to need more code than that. Post a few lines prior to 17.