Search and keep what i need from a text,,,,

[123456programmer]

hey. I need to make a script that can make a search for me.
let's say i have this following text:

he said: "i don't know why this script doesn't work"

what i need to do is to get what is between the quotation marks.
what i thought to do is to first find -he said: "- then keep only what is following which means -i don't know why this script doesn't work"- then look up for the second quotation mark and only to keep what was before. and to repeat this search through all the text.

thanks in advance. any help will be appreciate.