Do we have a Console mode or a Log System to display the functions calling or the dynamic value changes for debugging purpose?

you can use the 'Log' function for file logging, or just display text on the screen using D.text(x,y,text);

ok, I was tryin out with the function. What's the range of the screen co-ordinate's system?
x : -1 to 1 ?
y : -1 to 1 ?

its in the documentation
X: -D.w() .. D.w()
Y: -D.h() .. D.h() (unless you specify otherwise Y is always in the range -1..1)

Oh, thanks, that seems to serve the purpose