RewriteMap not working in mod-rewrite

Question

I have been trying to do simple maping with RewriteMap directive in my htaccess, but for some reason i am getting error 500 everytime. my syntax is .. Options +FollowSymLinks

RewriteEngine on
RewriteBase /
RewriteMap name2id txt:nklist.txt
RewriteRule ^/name/(.*) /name_list_view.php?kid=${name2id:$1|NOTFOUND}

in nklist.txt :

1 David
2 Mark
3 Simon

the nklist.txt file is on the root of my website , same place where the htaccess is . As far as my debugging tells me that htaccess is not able to find the nklist.txt file, but any help would be thankful.