problem in programming

Projects General Guidance
1

dear Sirs

I have a problem with my new arduino board MEGA 2560.

when I upload my program it works carefully and everything is ok

but when I disconnect usb cable from board its memory is erased and I have to upload it again.

What should I do for it to hold the program even when the board disconnects from power supply.

thanking you in advance.

2

Normally the uploaded program remains on the Arduino when you disconnect the USB cable.

How do you know that is not happening ?
What tests have you done ?

...R