Thanks all,
I did not know this. I thought I msut have at least one year VISA of a country in which a VISA Office to which I am planning to send my application package is located. In the time of my application, I had 5 years working VISA in Singapore, so I applied and I selected Singapore VISA office. In addition, I sent a copy of my Singapore VISA to show that I have rights to stay in Singapore for 5 years. Actually, the copy was requested by the VISA Office check list.
Nevertheless, they have sent my application to Damascus, Syria, which is really far from here and I heared the processing time and conditions are really terrible there. Moreover, if they invite me for an interview, that will be another problem.
Lastly, I warmly appreciate your useful answers and helps.
I wish all the best for all of you.
Best regards,
Tracy