What do I say when I am asked why do I want a career change? I am trained in one field but I want to get into a different field and I don't know how to answer that question.

You always remain positive in an interview. Instead of saying you don't want to continue in the field you're in now, you would say something along the lines of "I'd like to position that would better suite my training and abilities." That way, you're not inferring that you're unhappy with your current employer, or that you're looking for something better. Just for something that you would be more suited for.

My approach is basically the following (to change from marketing to work as a paralegal):

At the time that I began my career, paralegal work was just emerging as a profession, and I suppose it did not capture my interest at that time because it was not very well defined or understood and there were not very defined qualifications for the position. I was on a college track, and seeking a profession where writing skills were well appreciated, and the hot field at the time was public relations and marketing communication, so I set that path for myself.

In the years since, I've enjoyed my career a great deal, but I also have developed a great interest in law and legal issues. I was ready to take the next step in developing further personally and in my career, and when I looked again at paralegal work, I found that it is now a highly professional and organized career, and that all of my skills are directly relevant to the work. I had the opportunity and interest to go back to school, and it all just fell together for me. I've earned straight As in the program, enjoy it tremendously, and am very eager to continue forward with my plans and land that first job in a law firm.

My hope is that I will find employment in a situation where my former experiences are valued, and where I can also continue to develop as a new paralegal. I can offer the best of both worlds - years of managing projects and deadlines, and generally learning how to function well in a work environment; plus, I have very current education and skills as a paralegal.