Combobox restricting values to optionlist

[jjh]

I am trying to restrict the value of a combobox (editor of a listgrid) to the available options from the optionDataSource.
I read (http://forums.smartclient.com/showpost.php?p=43760&postcount=2)
that I could simply test if getSelectedRecord() is null.
but how can I get hold of the combobox in the onEditorExit-Event. I can't use the one used for setEditorType, it is not the same.