title: Changing from frameset/frame to iframe
body: <p>I am refreshing an older generation server-based web application which makes extensive use of   framesets and frames. I understand why frames are bad and iframes a better, HTML5 compliant solution. </p>
  
  <p>What I'm struggling to achieve is the iframe equivalent of something easy to do with frames: a left 'menu' frame of fixed width, and a right 'content' frame which fills the remainder of width available, both with height 100%.</p>
  
  <p>With frameset it is simply: <code>&lt;frameset cols="300,*"&gt;...&lt;/frameset&gt;</code></p>
  
  <p>With iframes the "*" isn't allowed to specify the remainder, dimensions must be specified as either px or %. Percent sounds like it should be ideal but it is not: if I make the browser 4000 px wide I want all the additional space to go into the content, not the menu.</p>
  
  <p>Have searched widely and can't figure it out. I'm sure there's a simple css-based, non-js, HTML5-compliant way to do this, but I'm ignorant as to how. Thanks in advance.</p>