pan class="lineno">  141</span>&#160;    end</div><div class="line"><a name="l00142"></a><span class="lineno">  142</span>&#160;   <span class="keywordflow">case</span> <span class="stringliteral">&#39;preview&#39;</span></div><div class="line"><a name="l00143"></a><span class="lineno">  143</span>&#160;    preview = value;</div><div class="line"><a name="l00144"></a><span class="lineno">  144</span>&#160;    <span class="keywordflow">if</span> (~strcmp(preview,{<span class="stringliteral">&#39;none&#39;</s