Saving text as a variable

Here’s my issue. I want to save a string of text as a variable. My code is this:

_global.scene_txt = “btnHome”;

I am then using that variable in the code:

on (rollOut) {
slider.yMove = _global.scene_txt._y;

I’m creating a sliding menu selector on my site.

Slider is the name of my movieclip instance that slides along the menu.

“btnHome” is the instance name of the button that I want it to slide to.

I’ve tried to set the variable a couple different ways. Without the “_global.” I’ve tried using the “var” command. I’ve tried putting in the actual instance name (btnHome) in the second code and it works fine, which means it’s not a problem with the code elsewhere. It’s just not recognizing “_global.scene_txt” as “btnHome”

None of them have worked.

I’m still very new to flash, so any help is greatly appreciated. Or if you need more information…