Mouse position values

[jorge.conrado at cptec.inpe.br]

Hi,

I have 3D data array and would like to plot arbitrary cross section by 
cliking in my image. I was an IDL user and in IDL we have a cursor.pro 
that I used to get the X and Y positions on my image. I would like know 
how can I get the values of the X an Y position for two points (A and B) 
in my image and save thiese values.

Thanks,

Conrado