According to the PDF instruction, in order to modify their trend lines I will have to move my mouse over and click on the line to open up the modification box. I tried clicking on it and it seems that the line never existed at all. Any Oanda account holders can assists?
I use Oanda, but use metatrader for charting. I just opened up my Oanda to experiment with the trend line a little bit. if you put your cursor on the trend line and right click, it gives you a menu with several options. like moving, changing the end point, change the color, etc.
Well I trying doing what you said. I still can’t get it to work. It is as if the line never existed there at all. 
That’s strange. As a programmer the first thing I tell a user who is having problems is reboot. So you could try closing out Oanda and then start it back up again. They have a live chat helpline too that may be helpful.
Hey bro, thanks for your advise. It works again, for no reason. Probably bugs. Thanks for your attention! Happy trading!