If (/start/ .. /end/) Flip Flop Mechanism

Hi all

	I know there is a flip flop option but I'm not sure thats what I need..  
Here is what I want to do - and I have no idea how to do this.

Basically I have a section of text that I am doing a search and replace 
operation.  The problem is what if the search text doesn't exist - I still 
want to add it.

So the logic is if it exists in the region replace it, if you can't find it 
add to to it

if (/start/ .. /end/){
   s/^foo/bar/;

}
now what if foo didn't exist - bar still should be set!

Any ideas?

-- 

 Steven M. Klass
 Physical Design Manager

 National Semiconductor Corp
 7400 W. Detroit Street
 Suite 170
 Chandler AZ 85226

 Ph:480-753-2503
 Fax:480-705-6407

 steven.klass@nsc.com
 http://www.nsc.com

• If (/start/ .. /end/) Flip Flop Mechanism by Steven M. Klass
• Re: If (/start/ .. /end/) Flip Flop Mechanism by Todd A. Jacobs
• Re: If (/start/ .. /end/) Flip Flop Mechanism by Jeff 'japhy' Pinyan
• Re: If (/start/ .. /end/) Flip Flop Mechanism by Steven M. Klass
• Re: If (/start/ .. /end/) Flip Flop Mechanism by Tor Hildrum