I like to make wallpapers, but I dont want those lines from a picture. its not very beautiful I use micrografx picture publisher 10

what lines are you talking about?

she probably means the outlines of an image if you just put it on a balck background or something like this... what you need to do is to feather the outlines... in the programs I know you select the part around the image and set feather to around 20 and delete... another option is to erase around the picture outline with a very blurry eraser... or overpaint with a very blurry brush with the background colour... if you want many pictures to belnd into each other you need to blend them...
http://www.toxic-passion.net/tutorials/blendingimagespsp.html maybe that helps ya even if you don't use psp?