title: I want to use max where field name=something
body: <p>I want to use max clause to find the maximum value according to field name
  Till now i had used this</p>
  
  <pre><code>SELECT MAX(sl) FROM associate where br_code=$_REQUEST[br_code]
  </code></pre>
  
  <p>but this isn't worked</p>
  
  <p>Friend as from my question it is clear that i want to find the max value of the sl from a group of br_code name which should be selected from the where clause.</p>