Open popup when an item is entered

Hi there,

I want to open a popup in CRMUI for some sales order when particular item type eg: PA30 is selected with some item quantity. I used EH_ONSELECT but this is not getting triggred in IMPL class. But I identified that I am able to get Struct.Kwmeng is getting triggred in context node CN00. Now my question is how can I trigger popup from CN00 class, where in I used ONSELECT in IMPL with HTML so far to generate a popup.

Please give the required details and let me know if any issues in understanding the requirement.

Regards,