Help with Skript

[MrPandy]

So I am trying to help a friend with creating a in game rankup skript so i got the gui to work and all and when u click the emerald it takes the money and ranks you up but there is a issue with it taking the money even if u don't have enough....Ex: The first rankup rank is rogue it cost 5k they click the emerald and they rank up now lets say they have $10 after buying that rank and they try to rankup again it ranks them up because the manuadd command is in the skript but even if they don't have the money needed they still rankup and their balance goes negative. Now im asking does anyone know of a way to fix this ?

 

[Shape The Cube]

Does not seem you have included any checks on your player balances to ensure that it does not go into a negative balance.

Have a look through here http://njol.ch/projects/skript/doc/expressions/

 

[MrPandy]

He told me he already tried that it doesn't seem to work for him is there anyway you can write like the line i would have to put in or something cause i can't figure this out at all