where is the backlight dimmer?

[dansar]

dan@dan-HP-G60-Notebook-PC:~$ inxi -F
System:    Host: dan-HP-G60-Notebook-PC Kernel: 3.19.0-56-generic i686 (32 bit)
          Desktop: Xfce 4.11.8 Distro: Ubuntu 14.04 trusty
Machine:  System: Hewlett-Packard product: HP G60 Notebook PC version: PCID
          Mobo: Hewlett-Packard model: 3612 version: 09.67 Bios: Hewlett-Packard version: F.65 date: 12/15/2010
CPU:      Dual core Pentium CPU T4200 (-MCP-) cache: 1024 KB flags: (lm nx pae sse sse2 sse3 ssse3)
          Clock Speeds: 1: 2000.00 MHz 2: 2000.00 MHz
Graphics:  Card: Intel Mobile 4 Series Integrated Graphics Controller
          X.Org: 1.17.1 drivers: intel (unloaded: fbdev,vesa) Resolution: [email protected]
          GLX Renderer: Mesa DRI Mobile Intel GM45 Express x86/MMX/SSE2 GLX Version: 2.1 Mesa 10.5.9
Audio:    Card: Intel 82801I (ICH9 Family) HD Audio Controller driver: snd_hda_intel Sound: ALSA ver: k3.19.0-56-generic
Network:  Card-1: Realtek RTL8101/2/6E PCI Express Fast/Gigabit Ethernet controller driver: r8169
          IF: eth0 state: down mac: 00:1f:16:70:95:c4
          Card-2: Qualcomm Atheros AR242x / AR542x Wireless Network Adapter (PCI-Express) driver: ath5k
          IF: wlan0 state: up mac: 00:24:2b:b5:c5:1c
Drives:    HDD Total Size: 320.1GB (2.1% used) 1: id: /dev/sda model: FUJITSU_MHZ2320B size: 320.1GB
Partition: ID: / size: 19G used: 6.2G (36%) fs: ext4 ID: swap-1 size: 3.15GB used: 0.00GB (0%) fs: swap
RAID:      No RAID devices detected - /proc/mdstat and md_mod kernel raid module present
Sensors:  System Temperatures: cpu: 58.0C mobo: 57.0C
          Fan Speeds (in rpm): cpu: N/A
Info:      Processes: 180 Uptime: 37 min Memory: 768.7/2960.7MB Client: Shell (b