[Tex/LaTex] Removing horizontal black line in listings

Question

I'm using listings for code snippets and I can not seem to find a way to remove the horizontal line on the bottom of a listings environment.

My code:

\lstset{
        basicstyle=\scriptsize\ttfamily, % Standardschrift
        numbers=left,               % Ort der Zeilennummern
        numberstyle=\color{blue!20!black!30!green}\tiny\ttfamily,          % Stil der Zeilennummern
        %stepnumber=2,               % Abstand zwischen den Zeilennummern
        numbersep=5pt,              % Abstand der Nummern zum Text
        tabsize=2,                  % Groesse von Tabs
        extendedchars=true,         %
        breaklines=true,            % Zeilen werden Umgebrochen
        keywordstyle=\color{red},
        frame=b,         
%        keywordstyle=[1]\textbf,    % Stil der Keywords
%        keywordstyle=[2]\textbf,    %
%        keywordstyle=[3]\textbf,    %
%        keywordstyle=[4]\textbf,   \sqrt{\sqrt{}} %
        stringstyle=\color{blue}\ttfamily, % Farbe der String
        showspaces=false,           % Leerzeichen anzeigen ?
        showtabs=false,             % Tabs anzeigen ?
        xleftmargin=0pt,
        framexleftmargin=0pt,
        framexrightmargin=0pt,
        framexbottommargin=4pt,
        %backgroundcolor=\color{lightgray},
        showstringspaces=false,      % Leerzeichen in Strings anzeigen ?  
        inputencoding=utf8,
          literate={å}{{\aa}}1
                        {æ}{{\ae}}1
                         {ø}{{\o}}1      
}

Answer 1

This is caused by the line

 frame=b

in lstset. As described in the manual, section 4.11 Frames, listings can draw complete or partial frames around the listings, with single or double lines. b is for bottom, and draws a single line at the bottom of the listings.