I would be failing in my duty if I do not express my sense of obligation and gratitude to all those who have helped me in bringing out these programmes. I am very thankful to everyone who all supported me, for I have completed my books effectively and move over, on time. To begin with my heart goes in gratitude to thank God for all his blessings and minute to minute unperceivable guidance that I received during my long venture to the completion of books. Next, I would like to thank, from the core of my heart, my father, Late Sh. S.K.Sangal and my mother Smt. Lakshmi Sangal for giving me knowledge to be proud of, a strong work ethic and a never give up attitude. I would also like to thank my father-in-law Late Sh. I.P. Gupta who always stood by me and whenever I was under the clouds of doubt, he came forward to dispel the same in no time. Next, I owe much more than words could ever express, to my husband, Mr. Ravi Gupta, who always rendered me the necessary help, peace of mind besides motivating me to finish my books well in time. My sincere thanks are also to Mrs. Sajla Gupta, books editor and Mr. Sameer Jain, books reviewer who with the best of their efforts edited and reviewed the manuscripts. Last but not the least all my appreciations go to Mr. Gagan Arora, the books designer and his team, who all with their expertise and designing know-how designed the books in a manner that the lessons came out to be more lively and student friendly.