Hi Guys n Girls

My first time in Photoshop forum. Hoping someone can help me with something that is probablly really simple.

I have a TIFF image exported from Poser.  I want it to fade out from fully colour to greyscale, side to side.  I know its probably something very easy. I am using PS CS3.

I got as far as duplicating the background layer which is the original picture, and turning that to greyscale. Now I"m guessing i need some sort of gradient.. but ..... I dont know how .... and i swear i am NOT blonde guys:)

Anyone help?

Drky xxx