How is this done?
find[img_] :=
centerOne =
ImageTransformation[src, img, {200, 200}, DataRange -> Full,
PlotRange -> {{0, 1}, {0, 1}}], bin =
Dilation[EdgeDetect[centerOne], 3],
components =
ComponentMeasurements[
bin, {"Centroid", "Area", "FilledCircularity",
"EquivalentDiskRadius"}, #2 > 100 &];, Show[centerOne,
Graphics[{Thick {If[#[[3]] > 0.2, Red, Blue],
Circle[#[[1]], #[[4]]]} & /@ components[[All, 2]]}]]

Moduleand separate them with a semicolon. The output of the last statement will be the return value of your function. Take a look at other answers from this site; I'm sure you'll find examples of this style. – MarcoB Jan 31 '16 at 04:47