Auto calc bug, sheet limitation, or other?

I'm trying to add a Flat-Footed condition to the pathfinder sheet. Mark G. helped me out with a formula to use. This seems to work in that it will pass the correct value for @{condition-Flat-Footed}, however the auto-calculated attribute, normally "0", becomes blank as soon as I toggle the @{condition-Flat-Footed} checkbox. Not sure what the issue is. Any suggestions? Thanks simplified code; Checkbox to create the @{condition-Flat-Footed} attribute <input type="checkbox" title="@{condition-Flat-Footed}" name="attr_condition-Flat-Footed" value="[[ {floor(@{DEX-mod}),0 }kh1} ]]"/> This just displays a number to indicate a condition(s) are being applied. Normally this displays "0" if no conditions are checked. <input name="attr_conditions-apply" title="This is the total penalty to various scores you are currently experiencing due to conditions." type="number" value="(@{conditions})" disabled><br>Conditions This is the auto-calculated attribute. <input name="attr_conditions" title="@{conditions}" type="hidden" value="(0 - abs(@{condition-Flat-Footed}) )">

SOLVED! <a href="https://app.roll20.net/forum/post/2143478/formula-needed-for-character-sheet-value-attribute/#post-2146837" rel="nofollow">https://app.roll20.net/forum/post/2143478/formula-needed-for-character-sheet-value-attribute/#post-2146837</a> Brian said: You can't use a group modifier like kh1 in an autocalc field. You can however use the construction A + B + abs(A - B) / 2 to get max(A, B). See here: <a href="https://app.roll20.net/forum/post/882997/#post-917740" rel="nofollow">https://app.roll20.net/forum/post/882997/#post-917740</a> Vince said: You hit the mark Brian. I changed this value ="[[ {floor(@{DEX-mod}),0 }kh1} ]]" to value="( ((@{DEX-mod} + 0) + abs(@{DEX-mod} - 0)) / 2 )" problem solved! Thank you very much guys. Much appreciated.