local rx = 'name="([^"]*)"%s+value="([^"]*)"%s+checked="checked"'
local s = '<li name="n1"\nvalue="v1"><li name="n2"\nvalue="v1" checked="checked"><li name="n3"\nvalue="v3"   checked="checked">'
for name, value in string.gmatch(s, rx) do
  print(name, value)
end