ActionScript 3.0 :: Multiple Instances Of A Class Having Conflictions?

I have a "Window" class, which will create a window with the parameters you specify. One of the functions inside of that class is to place an element inside the window - something such as a text field, button, etc.

Now my issue. I've created two windows with different names, slightly different parameters, etc. I am adding a text field to each one. On the screen, both text fields show up (have borders enabled). I can refer to both windows using getChildByName(), but for one reason or another I can only find one text field using the getChildByName method. The other one will give me an error.... "Cannot access a property or method of a null object reference."This is the code that I use to add a Text Field, keep in mind this is inside the window class:

ActionScript Code:
public function element(builder:Object) {
switch (builder.type) {
case "static_text" :

[code]....

This code is repeated twice, for different windows. The only thing that's different about them is their names, which are slightly different. It seems that whichever text field I add first gets to stay, while an subsequent ones appear on the screen, but I cannot refer to them. I've tried switching around the window definitions and that does seem to be the case.