PHP function to filter between two tags

We are working on a PHP-driven web site that will automatically censor and remove information for users that are not logged in.? We need a reliable function to filter text and remove parts between and tags and return the result. ## Deliverables Here is a detailed view of what we need.... #### Begin pseudo-cdoe function censor_html($input){ // You create this part return $something; } $sample='This information is not a secret. **The secret phone number is (123) 555-1234. _Do not give it out_**? The mail phone number is (123) 555-1000.'; echo censor_html($sample); /* Returns only: This information is not a secret.? The mail phone number is (123) 555-1000. */ #### End Everything between and is removed from the string. - Note that other HTML tags my be between and . - and may appear on different lines - and will appear in lines with non-private text. - We are responsible to calling the function when appropriate.? You are not required to integrate with our system... only create a fast, efficient function to accomplish this goal. - Function cannot be klunky.? Should execute in 30 milliseconds or less from the command line interface (excluding time for the HTTP daemon) for a 10k byte input on an idle 2.8GHZ Linux core.? ## Platform PHP (LAMP Stack)