You can set a breakpoint on the code line you want to jump and then press Run (F5)
Go to the line you want to jump to (it must be a script line, not a comment or empty line). Then set a breakpoint using CTRL + F2 or using the hand button in the toolbar.
Then press Run button or F5 to start automatic execution
thinBasic will execute the script until it will encounter a breakpoint and than stops
Another useful way for complex script is to add breakpoint comments directly into your source script using right click into thinAir and then "Insert Code Block" / "Debugger BreakPoint" or inserting them manually.
Breakpoint comments are special comments starting with '[breakpoint] text. Example:
'[breakpoint] Stops just after main loop
They are intercepted by thinDebug when it starts.
When inside thinDebug, pressing Run (F5) will execute your script but it will stop execution when it encounter a break point.
Hope this help