Script goes directly to and stops at "else if"

Hi!

I was wondering if some of you could tell me why this script is not executing the first If statements but directly going to else if and issues message in the log:

                    Stopped script processing after method session.utils.showOptionDialog().

The logic behind this is to check whether vendor with tax number exists

1) if such tax number exists, there is an additional pop-up to confirm the selection of vendor

      -  further there are two options:

                                                      * if vendor is confirmed - "enter" brings you to next screen for choosing variable

                                                       * if vendor is not confirmed - "enter" must be pressed one more time to get to the next screen (status bar shows                                                            message that vendor is not confirmed)

          - but in case vendor with such number doesn't exist, while search help window is opened, there is a message in the status bar.In this case I want                to close the search help window, go back to the last screen and issue informational pop-up.

but whatever number I enter, system gives the informational pop-up and error into the log:

Sometimes it also issues messages that step3 and step4 failed to fire action.

Any help is welcomed.

Thanks,

Diana