RewriteEngine on
RewriteCond %{HTTP_HOST} ^www\.pronetmedia\.cz [nc]
RewriteRule (.*) http://pronetmedia.cz/$1 [R=301,L]
RewriteCond %{HTTP_HOST} ^www\.pnm\.cz [nc]
RewriteRule (.*) http://pronetmedia.cz/$1 [R=301,L]
RewriteCond %{HTTP_HOST} ^pnm\.cz [nc]
RewriteRule (.*) http://pronetmedia.cz/$1 [R=301,L]