Can somebody tell me how to add codes on the action replay by simply copy..

You must press the upgrade software button on the action replay window.

Then you right click the Diamond menu and press add cheat.

Install the Action Replay Code Manager from the installer disc. Now take the USB cable that also should've come with your AR and gently insert the small end into your AR, making sure there is no game card in your AR and DS. Insert the other end of the cable into your computer's frontal USB port(the back ones work as well, but are not as easy to access) and turn on your DS. Now you must install the cable. To do this, right-click the "My Computer" icon and select "Properties", now "Hardware", you should see a button labeled "Device Manager", click on it. At the bottom of the list, you should see either "USBIO controlled devices" or "NDS Link". Sometimes you'll see a yellow "?" or "!", this means it must be installed. If this is so, right click on it and select "Install". Follow the on-screen instructions to install. Once it's installed, open the code manager, on the left you'll see "Waiting for DS", once it finds it, you'll see "NDS Codes" and under that, "Loading". Once it's finished loading, you'll see all of the codes that have been added. To add codes, right click on "My Custom Codelist" in the right-bottom box and select "Add New Game", from there it'll ask for the game's name, and ID(for Pokemon Diamond, enter 'ADAE' in the left box, then '636791C0' in the right). You can now drag all the codes you've entered manually into your codelist(if you are only updating Pokemon Diamond, say, you need only to drag codes from that game into your codelist). Once all the codes you have on that game are in "My Custom Codelist", you can start adding new codes. To do this, right-click on the game you are adding to and select "Add New Cheat". Type the code's name in the top box, and paste the codes into the bottom box. Once you have finished adding codes, drag the game(NOT THE CODELIST) into the left box. A dialogue box will appear and say "This game already exists, do you wish to replace it?" select "Yes" and there'll be another under that that will say "Deleting game "Pokemon Diamond" from Action Replay..."
And then, "Writing game "Pokemon Diamond" to Action Replay..."
Now all the codes are in your AR, as well as in your codelist.
You can also click "Codejunkies US games" or whatever version you're using to get basic codes.
To disconnect: Close the code manager, then shut off the DS and disconnect it from your computer.