my javascript variables wont add correctly

my javascript variables wont add correctly

References

Reference NO 1

http://stackoverflow.com/questions/15165906/my-javascript-variables-wont-add-correctly

Reference NO 2

http://www.codecademy.com/forum_questions/4fc75b18975b65000305e006

Reference NO 3

http://www.htmlgoodies.com/beyond/javascript/javascript-tutorial-variables-and-operators-explained.html

Reference NO 4

http://www.w3.org/wiki/JavaScript_best_practices

Reference NO 5

http://www.standardista.com/javascript/15-common-javascript-gotchas/

Reference NO 6

http://www.howtocreate.co.uk/tutorials/javascript/variables

Reference NO 7

http://net.tutsplus.com/tutorials/javascript-ajax/24-javascript-best-practices-for-beginners/

Reference NO 8

http://niel.delarouviere.com/2012/03/the-really-absolute-beginners-guide-to-host-node-js-on-heroku/