Need a little help

[chelsea1124]

Hello, Mcm Developers I'm looking for a little help with a plugin I'm creating (It's like a crate system but not).

Anyway, I need to add a bit to the code to where once the person clicks on a certain bit in the book it will open a sign GUI and in the sign, they will type the Answer to the Maths Question or riddle then it will do stuff I'm just not sure how to do the sign bit.

The showcase of the plugin at the moment to see how it works: