动态地向表单添加行而不重置上一行

Hi this is a second part to an early question. I need to add rows to a form consisting of a selection box. Each row of the form is a type of "Room" in a house and the user has to be able to add as many rooms as needed. I have it all working however if you fill in the 2nd room and then add a 3rd room it resets the selection box to its default for the 2nd room. I can see why it is doing this i just cant think of how to change the function so it keeps your previous selections intact. Note: i have the 1st row for the 1st room written in the HTML then this function(below) is called from a button click and adds the extra rooms.Hi this is a second part to an early question.