How to find out tags like [FNAME] in content field in php?

Question

I have taken field name content in my form in that I have used fckeditor.

in content field If i am entering like

eg: "Please add [FNAME] and Roll no [ROLLNO]"

and in place of the FNAME and ROLLNO the value should be come from db

Answer 1

  $content  = "Please add [FNAME] and Roll no [CONTACT_NO].....[here][EMAIL]";    
  $find     = array("[CONTACT_NO]"=>$contact_no,"[FNAME]"=>$name,"[EMAIL]"=>$email); 
  $newstr   = strtr($content, $find); 
  $body  = str_replace($content,$newstr,$body);