It also gives you a preview of what the script will look like after the changes (see Figure 5). If you do see any places where you don't want NetBeans to intervene, you simply remove them from the list of occurrences.
If you're in a hurry, another neat trick is to click on a variable and then press Control-R. This is a quick way of renaming a variable, which lets you modify all of the occurrences of this variable simultaneously. When you select a variable, NetBeans will highlight the occurrences of this variable so you can have a fairly good idea of what you are changing.