Nightshade

Hey, No problem! It can be frustrating from both ends: explaining to someone what to look for, and having someone who already knows stuff gloss over details. I figure everyone here, even the experts are always learning something, and I find I learn form helping others identify spottings. However, it all boils down to the fact that I"m looking at a picture and you can go back outside and get a good close look!

What I mean is the leaves almost look like bindweed aka morning glory vine, which would certainly point to S dulcamara, but only if they fenceline gets wet enough to have standing water for a time each year. S seaforthianum has pinnate leaves... meaning an odd number of leaves on a branch, with one at the end of the branch, and the rest opposite each other. If you are familiar with ash or alderberry, you'd know what I mean. However, there are dozens if not hundreds of nightshades all different, except for the very similar flowers

I'll take your word for it, even though I see more of a swirl pattern - like a morning glory vine, rather than pinnate

I can't find reference to this one being here in the US, although climbing on fences sounds like it's habit. Can you tell if the leaves are symmetrical as in the wiki link? http://en.wikipedia.org/wiki/Solanum_seaforthianum

Definitely a nightshade, but unless it was in wet marshy ground I'd look at one of the other species than dulcamara

check Solanum dulcamara