how to put negative integers in a section of a skill

[Yamuraiha]

For example in Blizzard Tower defend (it's a TD map made by Blizzard Entertainment) there is an aura that decrease enemy's defend. When I open that map to look how they made that aura, I saw that they use the armor bonus aura, but they put -6 in the section "bonus armor". But when I try to make the same thing it can't be done ?

 

[Juno**]

Hold shift key then double click the data field of your choice. After the data field opens, release the shift key and you should be able to input negative values.

 

[Yamuraiha]

Hold shift key then double click the data field of your choice. After the data field opens, release the shift key and you should be able to input negative values.

oh tks a lot