Item Script - Equip Armor and become Small size

[kaeyih]

I have a question
All monsters have different size, Large, Medium Small and demihumans are usually medium size.

If we put a script into Equipment, When u wear this armor, ur size become Small. Anyone know what should i write in script?

This doesnt work... so anyone can guide me pls? 
{ bonus bDefSize,Size_Small;},{},{}