   Point Selection Problem
  I have a number of pixels of a particular color.I need to choose a,already rendered, pixel , using mouse click and then change its color. Q1 .How to do this? Q2. I need to add dragging feature in my application where in, I need to move a particular ,already rendered, point to a new location.Presently, I am able to do dragging on the point drawn most recently. That is the last point.Eg: I have 3 points A,B,C with C as the latest point.I am able to drag C only but not B or A.Thank you.   