I have this question about the control triggers, I have this project that have textbox, using it's textChanged function and setting the autopostback in to true.

Now, when I trace the command I have notice that the function have been triggered twice, and I just want to know now
how that happens and how I can set this to trigger only once.


Are you typing into this textbox or setting it programatically? If typing, then the event would be triggered for every key press, and thus you will experience multiple successive postbacks.

If any other function/event occuring is changing the text in code on PostBack, it could be triggering an additional postback from that event as well.

Just food for thought.