Newbie Question-Quoting SQL

I have some old forms that I used for MySQL a few years ago, and I'm
trying to use the with postgres, but I keep on getting a message that
the query failed.

The connection string seems to be okay:

$link = pg_connect("host=localhost port=5432 dbname=toms_stuff
user=postgres password=********");

The query string, however, seems to be messed up.

  $result = pg_query ($link, "Select * from Author");
  if (!$result) {
      echo "Query failed.\n";
      exit;
  }

I assume the fault is in how the Select statement is quoted, but I
can't see what I'm doing wrong.

Any suggestions will be appreciated. Also can anyone give me a general
idea of the rules for quoting postgreSQL in PHP?

Thanks for any help you can give.

Tom Hart