Remove the last comma. IE has problems decoding JSON when a last comma is appended.

{           
            'size' : 960,           
            'tooltips' : 'floating',            
            'cities': false                 
        }

Remove the last comma. IE has problems decoding JSON when a last comma is appended.

So your JSON part has to look like that:

{           
        'size' : 960,           
        'tooltips' : 'floating',            
        'cities': false                 
}