Create the correct Javascript loop?

I am creating a form which contains a 'select' drop down option. 'onChange' I want to create a Javascript function which will create a number of 'div' depending on the value of the drop down option ie if dropDown = 1, create 1 div.

But instead of creating multiple if statements to tackle this problem I am hoping there is a loop that i can use?

I need to be helped in the right direction, many thanks in advance.