# MEP - How to set dialog box values **URL:** \ **Category:** Packages\ **Created:** [December 21, 2015, 2:51pm UTC](https://forum.dynamobim.com/t/mep-how-to-set-dialog-box-values/2763 "2015-12-21T14:51:46Z")\ **Posts on this page:** 1\ **Showing post:** 17
**Author:** ![GregX](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/gregx/32/56837_2.png) [@GregX](https://forum.dynamobim.com/u/GregX)\ **Post date:** [February 21, 2018, 1:35pm UTC](https://forum.dynamobim.com/t/mep-how-to-set-dialog-box-values/2763/17 "2018-02-21T13:35:26Z")
Hey everybody, excuse me if I bring this thread back to life after two years. I tried the linked dyn both in revit 2016 and 2018 but had the same result: the Loss Method and Loss Method Settings would change, but the calculated value Pressure Drop would not. i.e. If I input the value by hand the calculated value updates, but with python it does not. Should there be some kind of “update calculated value” code? something like "hey revit I changed the Loss Method Settings so you should recalculate the Pressure Drop value?"or is it not working with Dynamo 1.3? Thanks --- _[View the full topic](https://forum.dynamobim.com/t/mep-how-to-set-dialog-box-values/2763)._