Hi Jukka Rahkonen Thanks for the reply. Actually the add2 function is inside the code. I feel the browser excluded that portion the code was <http://osgeo-org.1560.x6.nabble.com/file/t384468/Untitled.png> -- Sent from: http://osgeo-org.1560.x6.nabble.com/GDAL-Dev-f3742093.html