reading firstname from addressbar

Hello everyone,
I am trying to read user firstname from addressbar in my activation page
my addressbar looks like this.

http://www.websitename.com/folder/?page_id=734firstname=myname

now in my php i write something like this

<?php
if (isset($_GET[‘firstname’])) {
echo “The variable value is “, $_GET[‘firstname’], “.”;
} else {
echo “Variable not set.”;
}
?>

but when page loads it echo else statement..
Please if anyone can help. Thank You.