I would like to put a circle as a border (stroke) around part of a photo saved in MY PICTURES folder but when I draw the circle and release the mouse the circle shows on a white background. But it is only the border I want to superimpose on my picture not the white field on which the border sits.

I want to get rid of that white background and to overlay the circle (in other words, the "empty" circumference of the circle) around the part of the picture I choose to place a border around.

I use Photoshop CS5 and Windows XP

Grateful if anyone can help a retired civil servant in his seventies with stepbystep instructions how to proceed as I have become rather slow on the uptake.

Many thks -- (In my mother tongue, Maltese, "Grazzi hafna")