[class^=R] > .settings {display:none;}
[class^=R] > .preprocess {display:none;} 
[class^=R] > .script {display:block; border:dotted 1px; padding:3px;} 
[class^=R] > .global {display:none;} 
.hide {display:none;}

/*
<div id="R1" class="R">
<div class="settings">
[[[FIG_OPTIONS]]] options for the R command png().  E.g. height=300,width=600
[[[SET_GLOBAL]]] comma-separated list of variables to pass to other blocks
</div>
<div class="preprocess">
script that you do not want to show to users.
</div>
<pre class="script">
main script
</pre>
</div>

Following blocks can be placed anywhere. They are all optional
<pre id="R1_console"></pre>

<span id="R1_answer"></span>

<img id="R1_figure">
*/