Using global variable in imported MC

I want to load an external .swf into my main .swf, it will contain a textfield. However, in order for it to know what to put in that text field, it must pick up on a variable.

main.swf

_global.USERENTRY

now in order for my mc user_output to display _global.USERENTRY, what must I do?

being _global just doesn’t seem to be enough