JQuery :: Add A Function To Appended Html Strings?

I want to create a questions creation page. It has a Question Text Box and a Add Button.When users press the add button, there will be a newQuestion Text Box and a new Add Button appear in the next line. But the old Add Button will become a Delete Button and change its functionality.[code]I put all the Add Buttons and Minus Buttons into two different classes, ".buttonPlus" and ".buttonMinus".The .buttonPlus works well when the line is added by the main html. But it fails to work when it is added by the .append() function. It simply adds the .buttonPlus's CSS code to its button, but the$(".buttonPlus").click(function (event) {...} is NOT attached to the new buttonPlus.