url to new format - apache

Question

Given below is my .htaccess file. It is not working on localhost apache (www is root directory on C:/apache/www) "url" is directory and I want output like this
http://localhost/url/index.php?username=shah
to
http://localhost/url/shah
I change windows host file 127.0.0.1 localhost
& also enable mod_rewrite in httpd.conf file & AllowOverride none to AllowOverride All
& root Directory to C:/apache/www
//==============================HTaccess==================================//
Options:
# -MultiViews: Turns off multiviews so it doesn't interfer with our rewrite rules
# -Indexes: Stop directory listings
# +FollowSymlinks: Let out rewrite rules work
Options -MultiViews -Indexes +FollowSymlinks
<IfModule mod_security.c>
# Turn off mod_security filtering.
# SecFilterEngine Off
# The below probably isn't needed, but better safe than sorry.
SecFilterScanPOST Off
</IfModule>
ErrorDocument 404 /url/404.php
<IfModule mod_php5.c>
php_value register_globals 0
php_value magic_quotes_gpc 0
php_value session.auto_start 0
php_value safe_mode 0
</IfModule>
<IfModule sapi_apache2.c>
php_value register_globals 0
php_value magic_quotes_gpc 0
php_value session.auto_start 0
php_value safe_mode 0
</IfModule>
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /url/
RewriteRule ^([a-zA-Z0-9_-]+)$ index.php?username=$1
RewriteRule ^([a-zA-Z0-9_-]+)/$ index.php?username=$1
#RewriteRule ^view-content/([^/]*)/([^/]*)\.html$ content.php?pageid=$1&title=$2 [L]
</IfModule>
<IfModule mod_deflate.c>
AddOutputFilterByType DEFLATE application/x-javascript text/css text/html text/xml
</IfModule>
//==============================HTaccess==================================//
Please tell me what to do?

Answer 1

Try this:
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /url/
RewriteCond %{QUERY_STRING} username\=(.*)
RewriteRule index\.php$ /url/%1
Hope this helps you... :)

Answer 2

If you really want to redirect a request of /url/index.php?username=shah externally to /url/shah, try this rule:
RewriteCond %{QUERY_STRING} ^(([^&]*&)*?)username=([^&]+)&*(.*)
RewriteRule ^index\.php$ /url/%3?%1%4 [L,R=301]
Otherwise, for the reverse direction:
RewriteCond $0 !=index.php
RewriteRule ^[^/]+$ index.php?username=$0 [L,QSA]