Update initialConfig from within Controller

hi,

I'm trying to update combobox initial configuration from within my controller. I'm using the following code to overwrite my combobox initialConfig of 'multiSelect: true' from within my controller code.



var mainCombo = this.getMainCombo();

Ext.apply(mainCombo.initialConfig, {multiSelect: false});



Is this possible to do or how should I go about doing this?



thanks