Genetic: Change Item

[cerberus]

Hey Guys, I was trying to create a Tigers Foot Skin (5 Pointed Scale + 20 China).. and a message always appears something about "Synthesis" .. i dont know what it is and Actually I dont know what I'm doing. 
so anyway, got anything to solve my problem? anything will help. thanks! 

[Kiyoshiro]

I think the skill is supposed to ask you if you're sure you want to use those items to create something so you just click yes or no. Should be simple enough.