# Problem extending a ComboBox in Flash

**URL:** https://forum.kirupa.com/t/problem-extending-a-combobox-in-flash/306250
**Category:** flash
**Created:** [March 11, 2010, 6:50pm UTC](https://forum.kirupa.com/t/problem-extending-a-combobox-in-flash/306250 "2010-03-11T18:50:54Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![oneiros](https://avatars.discourse-cdn.com/v4/letter/o/ce73a5/32.png) [@oneiros](https://forum.kirupa.com/u/oneiros)
#### Post date: [March 11, 2010, 6:50pm UTC](https://forum.kirupa.com/t/problem-extending-a-combobox-in-flash/306250/1 "2010-03-11T18:50:54Z")

</div>

Hi all,

I’m currently working on a project, and in it I’m extending a ComboBox like so:

```auto
package test.dropdowns {
    
    import fl.controls.ComboBox;
    
    public class Propertytypes extends ComboBox {
        
        public function Propertytypes() {
            //populate here       
        }
        
        private function databind(){
                        
        }
    }    
}

```

I’ve stripped the class down to the basics to make sure its all working, but I’m getting the following error:

1017: The definition of base class ComboBox was not found.

Any ideas?

Thanks in advance,

Dave