photoshop crap

http://www.depiction.net/tutorials/photoshop/roundededges.php
if you want only one side rounded just deselect the other one.

jpg doesn't support transparency. Either save as .png or make the edges the colour of the background.

google

u need to make ur background to be the desired shape (when starting new project) or u cannot use jpg

you can use the eraser to clear the edges, like in paint?

you suck, stop

http://www.depiction.net/tutorials/photoshop/roundededges.php + make 2 layers then erase the one side so you get a rounded edge on one side only .-.

It will always have edges. No matter what.

you cant make a jpg edgeless

You cannot make a .jpeg file edgeless, because it doesnt support transparency. Save it as .png and make those edges transparent, they are still there, you only cannot see them. Another choice would be if you paint the edges in the colour of the background.

how can i make a jpg edgeless?

with magic :P