PixelSearch syntax

I need to have pixelsearch search an area of pixels that stretches across the screen and is one pixel tall.

Would I use (I am trying to search the line of pixels at 144):

pixelsearch(0 ,1050, 144, 144, 0x000000)
pixelsearch(0 ,1050, 144, 145, 0x000000)

pixelsearch(0 ,1050, 143, 145, 0x000000)

thanks,
Mysis