extending backlight timeout in T707

after a few seconds of inactivity, the phone turns its UI black in order to save battery... i want to extend this time (preferably not have it turn off at all)... after all the T707 is a clamshell model, if i leave it open it's usually for a good reason...

i see a BACKLIGHT parameter in LAYOUT_MAIN.XML but i don't know what to change it to (or if indeed this is what i need)

A2UPLOADER reports the following phone details:

ChipID:D900,EMP protocol:0401

PHONE STATE: "RETAIL"
FLASH CID: 0053
OTP LOCKED:1 CID:53 PAF:1 IMEI:35451803392489 CERT:RED
LDR:2009-04-21 18:20 1207-6251_DB3200_CS_LOADER_APP_SDRAM_R2A081
LDR CAPS:SYSTEM FLASH GDFS FILESYSTEM TA
LDR:2009-04-21 18:19 1207-6250_DB3200_CS_LOADER_ACC_SDRAM_R2A081
LDR CAPS:SYSTEM FLASH SIGNATURE AUTH

HI.
Have You solve the problem with backlight?