errors are not getting loged

[rkmr.em at gmail.com]

this is my virtual server configuration. the access log is working,
but the error log is empty and errors are not getting logged
how to fix this?
thanks

    server {
        server_name  XX.YY.com;
        listen 8070;
        access_log   logs/access_app1.log;
        error_log   logs/error_app1.log;

        location /nginx_status {
            stub_status on;
            access_log   off;
        }

        location /static {
            root   /home/mark/work/luvgifts;
        }
        location / {
            root   /home/mark/work/luvgifts;

            fastcgi_pass backend_luvgifts;
            include /home/mark/work/infrastructure/nginx_fastcgi.conf;
        }