Cropping an Image with draggable rectangle

Crops the Image from a draggable rectangle & displays it (after the figure is closed)

% Crops the Image from a draggable rectangle
% & returns the Cropped Image and its co-ordinates
%
% I is the Image to be cropped assumed to be in the
% matlab workspace
%
% w : width (default value : cols/2)
% h : height (default value : rows/2)
%
% EXAMPLES
%
% I = imread('circuit.tif');
% [O] = Crop_it(I);
%
% [O I_crop]=Crop_it(I,0);
%
% [O I_crop]=Crop_it(I,1,100,100);