# Can't access a null value ...error

**URL:** <https://forum.kirupa.com/t/cant-access-a-null-value-error/328140>\
**Category:** Uncategorized\
**Created:** [April 22, 2012, 11:50am UTC](https://forum.kirupa.com/t/cant-access-a-null-value-error/328140 "2012-04-22T11:50:58Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![learner\_7n](https://avatars.discourse-cdn.com/v4/letter/l/b2d939/32.png) [@learner\_7n](https://forum.kirupa.com/u/learner_7n)\
**Post date:** [April 22, 2012, 11:50am UTC](https://forum.kirupa.com/t/cant-access-a-null-value-error/328140/1 "2012-04-22T11:50:58Z")

</div>

Hi,

I am using datagrid (which is in my library) it is not on my stage. I want to change its alpha property to .5 using greensock as3. I am getting error with the following code. I don’t know how to modify the following code when it is in library.

TweenMax.to(data\_grid, 1, {alpha:.5, delay:1});

Thanks.