Multi-select not working in Firefox or Safari

[jgonz25]

I recently upgraded my Ext JS library from 2.0 Beta to 3.4. After the migration (nothing else changed) my multi-select function has stopped working.

On my site a user should be able to select multiple items from a list and then a drop down menu populates to allow the user to pull those specific items into another window (specified by clicking an option in the drop down menu). This is working in IE still, but in Firefox and Safari the check boxes looked checked, but the drop down menu does not populate.

After installing Firebug, it told me that in the following line, multiSelect was null.

var selectedOpt = Ext.get('multiSelect').getValue();

Why would this not be working in just Firefox and Safari after a library change??? Can anyone help me?

[mitchellsimoens]

Assuming you have selModel defined? singleSelect on the selectionmodel should default to false which means multi select is default.

[jgonz25]

I don't see where I have selModel defined on this page. So shouldn't it default to multi-select then?