How can I place 2 iframes next to each other?
<p>I need to create a page where I have 2 iframes next to each other with 100% height.</p>

<p>The left frame needs to have a fixed width of 140px and the right one needs to take the width of the rest of the screen. Keep in mind that both frames need to have 100% height.</p>

<p>Since there are different size screens I can't set a fixed with on the right iframe as I want it to take all the screen after the first 140px;</p>

<p>I kinds got it to work while using precentage. But the problem with percentage is the the left menu sometime show very wide</p>

<p>I created a fiddle to show you what I have done so far</p>

<p><a href="http://jsfiddle.net/mwg3j17d/16/" rel="nofollow">http://jsfiddle.net/mwg3j17d/16/</a></p>

<p><div class="snippet" data-lang="js" data-hide="false">
<div class="snippet-code">
<pre class="snippet-code-css lang-css prettyprint-override"><code>#main_block {
  display: block;
  width: 100% height: 100%;
}
#left_frame {
  width: 25%;
}
#right_frame {
  width: 75%;
}
#left_frame,
#right_frame {
  float: left;
}
iframe {
  box-sizing: border-box;
}
.b_footer {
  padding: 10px;
  width: 100%;
  background-color: blue;
  text-align: center;
  color: white: font-weight: bold;
}</code></pre>
<pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div id="main_block"&gt;
  &lt;iframe id="left_frame" src=""&gt;&lt;/iframe&gt;
  &lt;iframe id="right_frame" src=""&gt;&lt;/iframe&gt;
&lt;/div&gt;

&lt;div class="b_footer"&gt;
  Footer
&lt;/div&gt;</code></pre>
</div>
</div>
</p>

<p>As you can tell, there are couple of problems with my code.</p>

<ol>
<li>The footer background's color for some reason is also showing where under the iframs.</li>
<li>The second problem is that I am using 25% width for the left iframe where it should be set to 140px</li>
<li>Finally, the height of the iframe is not taking the entire height of the screen.</li>
</ol>

<p>How can I correct the problems mention above?</p>

<p>EDITED
I also tried to use Table to get the job done but the left iframe does not have the correct width. Here is an updated Fiddle to show you 
<a href="http://jsfiddle.net/mwg3j17d/19/" rel="nofollow">http://jsfiddle.net/mwg3j17d/19/</a></p>