I'm trying to set up a formula to adjust the left and right door reveals on a cabinet as needed. 

Here is the formula that is set up as the base formula for the Left Reveal in Edit Design Data:

=IF(G!Hinge_Institutional=1,Thickness_Left_Side-G!Door_Overlay_Institutional_Hinge,IF(OR(Left_Applied_End=1,Left_Filler_Width>0),G!Inset_Door_Drawer_Reveal,G!Default_Door_Drawer_Reveal), that formula gives me a 1/16" wide reveal to the left of the door, which is perfect.

I have created this Prompt: "Hold Door Short Left" and it's set up as a text box. 

So I tried this formula: =IF(G!Hinge_Institutional=1,Thickness_Left_Side-G!Door_Overlay_Institutional_Hinge,IF(OR(Left_Applied_End=1,Left_Filler_Width>0),G!Inset_Door_Drawer_Reveal,G!Default_Door_Drawer_Reveal)+(L!Hold_Door_Short_Left-G!Default_Door_Drawer_Reveal))

What that does though is it changes my Reveal to "0" when my Hold Door Short Left text box has a value of "0", and I understand why that formula does what it does. What I'm trying to do is have the formula ignore the Hold Door Short Left Prompt if the Value is "0" but I can't figure out how to do that. 

Sorry if this seems easy for most of you but I was tasked with trying to incorporate Microvellum without any prior training or know how with formulas and how they all work so while Microvellum itself is new and a lot for me, formulas and excel are also new and completely foreign to me as well. 

Thank you!