dhtmlxGrid and SplitAt

Is there a way to enable, disable, or change the frozen columns in a Grid, after it has been created? I know how to use SplitAt while creating the Grid, but I’m looking for ability to make a button for the user to “unfreeze” columns.

I have tried the following:
Set Frozen Column to 2
Set Frozen Column to 4
Set Frozen Column to 0

But with all 3 examples, my Grid just get messed up.

Is there something I’m doing wrong? Or is this not an option with the current version of dhtmlx (3.0 Pro).

This feature is not available.