I don't know how to enquiry the "informationtype" which are message and email? How to rewrite the below code?

$information = mysql_query("SELECT * FROM table WHERE informationtype='message'");
$row = mysql_fetch_assoc($information);
$result=($row['informationno']);

Your code is right.
Are you facing any error?

$information = mysql_query("SELECT * FROM table WHERE informationtype='message' or 'email'");

Correction...

$information = mysql_query("SELECT * FROM table WHERE informationtype='message' OR informationtype='email'");

I wonder how you guys understood the question. Am I that dumb?