My canon fd 50mm 1.8 lens will only focus close up...I can't bring anything further than 6 or 8 inches away into focus

Extension tubes will not affect the zoom range. They simply allow the lens to focus closer by moving the glass farther away from the film or image sensor. I use them for my own close-up work.

The 18-135mm will let you focus down to 0.45m for a maximum magnification of about 1:4.8. True macro is at least 1:1 (lifesize) so this lens can't really be called a macro.

If you mean the 50mm f/2.5 lens, this will let you get to 1:1.

you will more then likely need one but before you buy go back to the store you bought it from and see what they say

in manual mode, will not try to focus itself, my be the manual auto switch is faulty, or the focus related mechanism not rotating the lens, open the lens carefully check the focus motor and gear set (engine is the technical term)

Your not doing anything wrong, your Panasonic probably is using digital zoom (which is basically just cropping the picture imitating zoom). Your eyes sees similar to a 50mm lens so your 135mm lens is less then 3x zoom.
Do not be discouraged you will soon learn your cameras strengths and weakness.
Good Luck

If you're right "on top" of the subject - then, yes - it should indicate "macro". Macro focusing is for "very up close" photography and is exactly as you describe. You simply physically move the camera a little closer to or further from the subject to focus.

Not all lenses are capable of macro focusing. The vast majority of these non-macro lenses are required to be at least a couple (or more) feet away to focus. Macro lenses on the other hand can usually get just inches away - which is a great capability.

Enjoy your macro lens!

I had the same problem with my ef 50mm 1.8. I used it on a cold day and broke off one of the internal gears. I used it for almost a year before I got the guts to take it apart and fix it. There are instructions online on how to take it apart, scary at first but not that hard overall. I used a small drop of crazy glue on the gear, put it all back together and just like new.

yes thats a fair bet,,, it could only be the lens that took the brunt of the smack it had and its now jamming when you try to focus up on close ups,,,
try a difrent 50mm lens on it and find out if im right

http://www.fotomozaic.ro/artikel.php?idstory=225&s=1

In that case the linkage between the movable parts of the lens group and the focussing ring has failed.

What follows applies to most lenses; I have a Canon 50mm FD to hand but as it works perfectly I've not needed to dismantle it so far but have repaired many others.

When you turn the focus ring there are usually two pegs which engage into helical slots cut into the focussing ring, these are hidden within the lens and you won't see them unless the lens is dismantled. The pegs are usually rounded to make the passage along the helical slot even smoother and each one is fixed to the inner lens barrel by a screw. On older lenses, the grease inside can dry out a bit, especially if the lens remains unused, when this happens the pegs may either shear off or simply become unscrewed and drop off. The gummy grease may hold them so you won't always hear a rattling part inside.

To fix it, you carefully dismantle the lens to the minimum extent you can get away with. You'll need good light, patience and a set of good quality crosshead precision screwdrivers. Normally you start with the screws on the mounting flange and watch out for small springs and detent balls which tend to escape to freedom never to be seen again. Some of the screws are usually hidden beneath the rubber grip on the focussing ring, and you remove this to check by carefully lifting an edge and then rolling it back over itself. It may need re-gluing afterwards. Clean out dried grease as you go and apply a small amount of thick grease to replace it on reassembly: less is far better than too much! Some of the screws may need thread lock applied to them when they go back in, but you're better off leaving this as your first time lens repair usually has to come apart again due to an error in reassembly.

Be prepared to ruin this lens as it's your first lens repair. The good news is that auction websites have plenty of other cheaply and in full working order, just make sure to ask if the iris (aperture) works smoothly and snappily and that the lens does not have the dreaded lens fungus on the glass elements (a patchy white haze). You can also usually get these lenses for free on Yahoo FreeCycle and a camera body and other goodies normally come as part of the offer. FreeCycle is how I've collected various Nikons, Canons and Pentax SLRs and lenses over the last year to add to my existing Olympus gear.

I hope that I've helped you, if so please return the favour by rating my answer.

If the AF motor is still alive + spinning, this should be fixable without any replacement parts.
Following URLs might be useful:
http://www.flickr.com/groups/canon_50mm/discuss/72157603775874649/
And this one - detailed instructions how to dismantle this lens and fix the issue similar to yours.
http://www.fotomozaic.ro/artikel.php?idstory=225&s=1

Hope this helps - good luck!
Raf