add detail row for header

JamieM

In my table the first row uses colspan='2' such that each two columns in the second row have something some grouping in the first column, like the category. I want to add a click action on these categories that, when clicked, adds another row with some descriptions of what these categories mean.

demographics |deli |fruits |bread

transaction id | time |salami | bologna |apples |pears |white |wheat

1234 |12:30 |1 |0 |1 |0 |1 |0
2345 |13:20 |1 |0 |1 |2 |1 |3

etc. when I click on demographics i want it to open a row below that has some description of what demographics means. The categories do not do sorting so adding a click event shouldn't be a problem.

Thanks in advance!