# \_alpha trouble

**URL:** <https://forum.kirupa.com/t/-alpha-trouble/164908>\
**Category:** Uncategorized\
**Created:** [October 5, 2005, 10:17pm UTC](https://forum.kirupa.com/t/-alpha-trouble/164908 "2005-10-05T22:17:46Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![hernanhalvarez](https://avatars.discourse-cdn.com/v4/letter/h/ce73a5/32.png) [@hernanhalvarez](https://forum.kirupa.com/u/hernanhalvarez)\
**Post date:** [October 5, 2005, 10:17pm UTC](https://forum.kirupa.com/t/-alpha-trouble/164908/1 "2005-10-05T22:17:46Z")

</div>

I got a movie named “myMovie” with a property \_alpha = 100… next step is decrease 10% of alpha:

_myMovie.\_alpha -= 10;_

then **why** when I put _trace(myMovie.\_alpha)_, I get “89.84375”???

why???

thanx.