Client script error while refreshing component.

Client script error while refreshing component.

  
Hi,
I am using this coimponent in a list to allow user to select multiple file for upload , i also have a dropdon above the list and based on the dropdown selection i need to fill the list and for the same i am refreshing the list on dropdown selection and i am getting an javascript erro "Undefined is not a function" as i have the dropzon control in my list.
i observed the same issue with other javascript component also while refreshing .
Thnx in advance for anu help.