UNIX for Dummies Questions & Answers

Hi all!
I'm a newbie to shell scripting.
I want to create a script that will store a line from a text file in a variable so I can then use it to open firefox with that text in the address bar (the text file contains a list of addresses).
I have tried the following:

Code:

#!/bin/sh
a='sed -n 2p ~/text/text.txt'
firefox "${1:-$a}"

but it seems to open the address: "file:///home/MY_USERNAME/sed%20-n%202p%20~/text/text.txt".

Please help...

Replace the single quotes ' with backticks `

Code:

a=`sed -n '2p' ~/text/text.txt`

Cheers
ZB

Thanks a lot, zazzybob!
It works now!
Previously I didn't even know of the existence of backticks...
Again, thanks a lot...