Neptune^ posted this, and it works really well. I had the same problem, I have a widescreen resolution and I couldn't see the bottom buttons. But this one fixes it. Here's the code again.

dialog pastebin {
  title "Pastebin Uploader / Downloader"
  size -1 -1 386 283
  option dbu
  box "Upload:", 1, 2 0 226 72
  text "Name:", 2, 11 9 16 8
  edit "", 3, 30 8 67 10, autohs center limit 0
  text "Private sub-domain:", 4, 101 10 49 8
  edit "", 5, 152 9 68 10, autohs center limit 0
  text "Highlighting:", 6, 11 22 33 8
  combo 7, 44 20 75 60, size drop
  check "Private Paste?", 8, 122 21 45 10
  button "Browse file...", 9, 184 45 42 11
  edit "", 10, 12 46 170 10, autohs center
  text "How long should your post be retained?", 11, 12 35 96 8
  radio "a day", 12, 110 34 24 10
  radio "a month", 13, 134 34 30 10
  radio "forever", 14, 165 34 28 10
  button "Preview!", 15, 11 57 50 12
  button "Upload!", 16, 63 57 50 12
  box "Download:", 17, 231 0 153 30
  text "Pastebin URL:", 18, 238 7 34 8
  edit "", 19, 274 6 106 10, autohs center
  check "Load to remotes?", 20, 238 17 52 10
  button "Preview", 21, 299 17 40 11
  button "Download!", 22, 340 17 40 11
  edit "", 23, 2 74 382 195, multi return hsbar vsbar
  box "Information:", 24, 231 30 153 42
  text "", 25, 237 37 144 32
  button "Close Dialog", 26, 139 270 60 12
  button "Clear Screen", 27, 201 270 60 12
  button "Copy to Clipboard", 28, 263 270 60 12
  button "Go to line...", 29, 325 270 60 12
  link "", 30, 250 43 125 7
}