[Closed] render bake white background . help

i want in script use render() command and rendered a jpg or a dds format bitmap file with a white backgroud instead of black background . the render command is like this :

 
render renderType:#bakeSelected vfb:on filterMaps:on antiAliasFilter:(catmull_rom()) \ 
	 to:renderBitMap renderer:#production quiet:on 
 

we can get a white background in max when use max render button . but i dont know why it cant works in render command . i have changed the background to white , or use a white file as background .

addition :
in VFB it shows a white background ,but when save to file , only tga format ok . jpg and dds file will remain the blackbackground .

if u save it manually in vfb as jpg or dds , will be ok with a white background .

thanks for help me .

added at 2006 05 06 .

now i know how to save the bitmap show in vfb . but when save it , i have to lost the padding of the map in bake process .

 obj.InodeBakeproperties.nDilations=thePadding 

ennnn , make me puzzle now .