Words fail me to express my deep sense of gratitude and indebtedness to Mr.Rajesh Khanna (Lecturer, Vaishnoo Maa Computers, Patiala) for his mature, able and invaluable guidance, his all out help, painstaking efforts and deep insight into the problem and thus improving the quality of this work at all stages, for his persistent encouragement that helped me to present this report in the present form.
I am also thankful to my colleagues Mr. Gurpal Singh and Vikram Gupta for their continuous encouragement during the study.
My special thanks are due to Mr. Rajesh Khanna(Lecturer, Vaishnoo Maa Computer, Patiala) who helped me directly or indirectly in the various stages of this study.