Have you gone through the leave module documentation available at http://support.wmlab.in/support/solutions/articles/17000017256-configure-leave-types & http://support.wmlab.in/support/solutions/articles/17000017257-all-about-leave-module.
Let us know if you still need any help.
Thank you very much for your reply. I have gone through that. My problem is when i click on save, the leave does not get added even though it says 3 leave remaining (i set the leave as 3). Nothing gets deducted nor can i approve. I am guessing it's something i did wrong and I know it's probably very easy to resolve. I just don't know why it won't work.