I still can't figure out a direct way to do this, graphics and all, although I think others can, but here's how I put a complete screenshotted image on a post. This works on Firefox, btw. I'll bet there's another way than this, but bman69 taught me this method (I broke it into a blow-by-blow list):
-start your message or reply on the forum
-screenshot the page with the image you want to post (I found that you have to make sure that the whole image shows! --no sliding down is available)
-go to your computer's start button; click Accessories; click Paint
-paste the screenshot onto the Paint window
-crop to get the actual image that you want
-use the airbrush or erase functions to hide personal info
-name the image and save to your Pictures file
-in a new window, open a hosting site. bman suggested www.imageshack.us, and that's what I use.
-find the text box with the radio buttons above, and click the Upload button and then Browse. This should open up your Pictures file. Find the image you saved and select it. You'll see its file name appear in the text box.
-click Host it!
-slide down all the way to near the bottom, and find the box next to where it says Hotlink for Websites. Highlight the URL in the box and copy/paste it to your forum message or reply.
-(You're now back on your forum post.) Click Preview Post and see if shows up. If it doesn't, I just go have a drink.
To screenshot, there is a button that says PrtSc or some such, on the top right of your keyboard. It's up above delete on a desktop, and above the + sign on my laptop.
-start your message or reply on the forum
-screenshot the page with the image you want to post (I found that you have to make sure that the whole image shows! --no sliding down is available)
-go to your computer's start button; click Accessories; click Paint
-paste the screenshot onto the Paint window
-crop to get the actual image that you want
-use the airbrush or erase functions to hide personal info
-name the image and save to your Pictures file
-in a new window, open a hosting site. bman suggested www.imageshack.us, and that's what I use.
-find the text box with the radio buttons above, and click the Upload button and then Browse. This should open up your Pictures file. Find the image you saved and select it. You'll see its file name appear in the text box.
-click Host it!
-slide down all the way to near the bottom, and find the box next to where it says Hotlink for Websites. Highlight the URL in the box and copy/paste it to your forum message or reply.
-(You're now back on your forum post.) Click Preview Post and see if shows up. If it doesn't, I just go have a drink.
To screenshot, there is a button that says PrtSc or some such, on the top right of your keyboard. It's up above delete on a desktop, and above the + sign on my laptop.
Thank you! Yours turned out perfectly. I'll try that. Phew. what a chore, but worth it. 
And in F.F. even. coolo.
coolo.