Ruby in Watir

I have troubling getting out from drop down selection line.
Since there are html coding which calls "onchange" function to populate a depended drop down. So script got stauck in the inbuild function "set".

I have tried to set the value from the below given options,
1. set
2. select
3. select_value

But still it get stauck and focus does not exist.

eg:
line 1. dropdown1.set "Area" (After selecting this, second drop down will populat with the options by calling "DS sources". From this line script get stuck.):mad:
line 2. dropdown2.set "School"

If anyone knows how to handle this, please let me know.

This calls pega activity whcih handles the drop down options.
script got stuck, since the options are appearing directly.
Once the operator selects, it calls the activity and populates the values.

If anyone knows how to handle this. let me know.
Thanks.