Changing value in a dropdown box

I have four different dropdownboxes that i want to link togheter. The first box is Age, and holds 3 values. {14-15 year, 16-17 year and '19 or above'} When choosing one of these values, the Grade dropdown get populated with {Blue belt, Red belt, 1. dan, 2. dan, 3. dan, supporter, and Coach} [When choosing 14-15 years -> Blue belt, red belt, [login to view URL]] [When choosing 16-17 years -> blue belt, red belt, [login to view URL], [login to view URL]] [When choosing 18 or above -> blue belt, red belt, [login to view URL], [login to view URL], [login to view URL]] When you have made your selection in age and grade, I want the Gender to populate with the options: Male, Female And finaly, but yet the most tricky part: The dropdown for weight class. [14-15 years -> blue, red belt or [login to view URL] -> male -> -52kg, -58kg, -63kg, +63kg] [14-15 years -> blue, red belt or [login to view URL] -> Female -> -58kg, +58kg] [16-17 years -> blue and red belt -> male -> -63kg, -71kg, +71kg] [16-17 years -> blue and red belt -> female -> -52kg, -58kg, +58kg] [18 or above -> blue and red belt -> male -> -63kg, -71kg, -80kg, 80kg] [18 or above -> blue and red belt -> female -> -52kg, -58kg, -63kg, -70kg, +70kg] [16-17 years -> [login to view URL] and [login to view URL] -> male -> -63kg, -71kg, +71kg] [16-17 years -> [login to view URL] and [login to view URL] -> female -> -58kg, +58kg] [18 or above -> [login to view URL], [login to view URL], [login to view URL] -> male -> -63kg, -71kg, -80kg, +80kg] [18 or above -> [login to view URL], [login to view URL], [login to view URL] -> female -> -58kg, -63kg, -70kg, +70kg] Not a difficult task, but it is timeconsuming because of all the different classes.