Join 2 parts into 1

Hi,
I recently scanned a poster but it was too big so I scanned twice to get the full of it. With PS7 I wonder if possible to re-join them as the original ?
I tried the "basic" way of copy and paste which is copying 2 parts into a new file but the outcome not look right.

is there a better way ?

thanks

How does it not look right? Copy + paste the second part into the first one, enlarge the canvas if necessary, and just move the second part as needed until it looks right. Zoom into the image if you're not sure if you got the placement right.

I think what he means is that it doesn't line up cause he can't get the scanning down perfectly

when I line them up the gap isnt right and not close enough. Very noticable if the pic were broken in half.
" can't get the scanning down perfectly" you mean I have to scan parts exactly and no overlapping ?
what Iam trying to do to find out here is that how I can move those parts until I get a perfect line .

well thats just up to your eye,

No what I am sayign is the reason copy and paste doesn't work is because when the scannign was done it probably didn't scan perfectly in 2 halfs

use your arrow keys to move selections pixel by pixel, makes for a way more accurate line up

Rather than trying to create the perfect match, try this trick...

1) Scan both part, but this time make sure than the outcome can overlap each other, in other word the part where they join should be on both copy...
2) Now in Photoshop open one of the images...
3) Change the canvas size to the size of your poster...
4) Copy tour second part
5) On you second part create a layer mask
6) Switch to your mask
7) In your mask, select the overlapping part
8) Now use you gradient tool to create a black to with gradient...

Now the overlapping part as a softer transition, so the exact edge are now harder to see

9 Use the arrow key to make a good match...

Hope this help you...