SKILL code to change all the existing Metal layers to its corresponding fillBlock layer

I'm a very beginner to the SKILL scripting, so just looking out for help to write a SKILL code to change all the existing Metal layers to its corresponding fillBlock layer in my layout.

As a start i wrote a few lines to check if the selected metal is "m2" in my layout

and to print "Layer name is m2" if it is

& if it is not, and print "Layer name is NOT m2"

The code is below, but its not doing what i intend it to, please help me fix it:

procedure(MetalToFillBlock()
let((m2)
if(geGetSelSet()~>layerName == m2
then
printf("Layer name is m2")
else
printf("Layer name is NOT m2"))
);let
);procedure