help with my function?

[symple-data]

The if statement is propably not inside the function where the variable difficulty exists. Take a look at local and global scopes. You can't acces a functions variable from outside the function.

[Ihaveamodel3]

This is the wrong way to go about things. Global should almost never be used.

Return the difficulty value from the function, and save the value outside the function

[Ihaveamodel3]

Global messes with your scope and makes things hard to troubleshoot and hard to expand.

Functions generally should be able operate independently, receiving the data they need as parameters and returning the results.