How can I make a 404 not found page redirect to the index?

I recently bought a site that has over 1k pages indexed in google, well I am adding a new script to it so all the pages that are indexed in google will not be a valid URL, so my question is what would I put in the .htaccess to make all those not found pages redirect to the home page?


Help would GREATLY be appreciated as this is kinda big thing!

Thanks!!!!!!!!!!!!

 

ErrorDocument 404 /

perhaps this would work.

 

Thanks, how would I put that though,

like

ErrorDocument 404 / /index.php

Code (markup):

^ Anything like that or is the second slash not nessecary?

 

no just the following

index.php not required