# Access of undefined property

**URL:** <https://forum.kirupa.com/t/access-of-undefined-property/274507>\
**Category:** Uncategorized\
**Created:** [October 30, 2008, 7:11pm UTC](https://forum.kirupa.com/t/access-of-undefined-property/274507 "2008-10-30T19:11:39Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![kritikal](https://yyz1.discourse-cdn.com/flex011/user_avatar/forum.kirupa.com/kritikal/32/1699_2.png) [@kritikal](https://forum.kirupa.com/u/kritikal)\
**Post date:** [October 30, 2008, 7:11pm UTC](https://forum.kirupa.com/t/access-of-undefined-property/274507/1 "2008-10-30T19:11:39Z")

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Hey guys,

still pretty new to AS3 so go easy on me 😛

I was wondering how do you change the properties of a movie clip from a class that isn’t the Document Class.

say I have text\_mc on the stage and I want to change it’s alpha to 0  
If I do text\_mc.alpha = 0; inside of the Document Class it works fine but if I do it in another class I get this error  
1120: Access of undefined property text\_mc

any ideas how to fix this?