Assigned new w2toolbar object to a panel
    assignToolbar(panel, toolbar)
    
    
        | panel | string, name of the panel | 
    
        | toolbar | string or object, toolbar to assign | 
    
 
Description
The first argument 
panel is the name of the panel. It can be one of the following:
    - top
    
- left
    
- main
    
- right
    
- preview
    
- bottom
Initially you can set a toolbar object for the panel when you initialize it in the following way:
However, if you already have a w2toolbar object created, you can assign it to the panel with assignToolbar methods. If second
argument 
toolbar is a string, it will look for toolbar in the global w2ui object.