Combobox changes button?

hi, I would like to start by thanking everyone for their help in the past. I find this forum to be very usefull.

im new to actionscripting and am having trouble with the following:

I have a combobox with three labels. I also have a button which is linked to an external site.

As a user selects one label i would like for the getUrl value for the button to be changed. Is this possible? How would i accomplish this ?

Thanks in advance for your help in this matter