There is other way... actually it works.

While booking ticket, mention that your parents need wheel chair.. (it does not cost extra money). Thats it!

And your parents will arrive here without having to speak one single word .. they dont need to walk one single step.. At every terminal, there will be someone standing at the door of plane with transport tool, and they will be taken to another plane.. everything is taken care. It is like urgent Fedex delivery system..

It works. Some of my friends have done this trick to bring their parents here.