covariate and k-extent determination + 'clpos_extent' error

[Tara-FD]

I have three questions about the CanLab toolbox:

1. Is there a way to determine a k-extent (to choose specific regions with k voxels as significant) for the toolbox?

2. How can I enter my covariates in the toolbox?

3. when I run the mediation_example_script_1.m (and also mediation_example_script_2.m) script, I get the following error:

Error:File: mediation_brain_results.m Line: 295 Column: 35
Identifier 'clpos_extent' is not a function or a shared variable. To share 'clpos_extent' with nested function, initialize it in the
current scope. For more information, see Sharing Variables Between Parent and Nested Functions.

Error in mediation_brain_results_all_script (line 238)
[clpos, clneg, clpos_data, clneg_data, clpp2, clnn2] = mediation_brain_results ...

Error in mediation_example_script_1 (line 80)
mediation_brain_results_all_script;

Would you please guide me how to solve this error?