Question

I am trying to achieve auto resizing of the 2nd iframe in this code,

Any help would be appreciated.

CSS

* {
    margin: 0;
    padding: 0
}
html, body {
    height: 100%;
    width: 100%;
    overflow: hidden
}
table {
    width: 100%;
    table-layout: static;
    border-collapse: collapse
}
iframe {
    width: 100%
}
.header {
    border-bottom: 1px solid #000
}
.content {
    height: 100%
}

HTML

<table>
    <tr>
        <td class="header"><div><h1>Header</h1></div></td>
    </tr>
    <tr>
        <td class="content"><iframe name="iFrame1" height="85" src="Materials AU Stocked Header.htm" scrolling="no" frameborder="1"></td>
    </tr>
    <tr>
        <td class="content"><iframe name="iFrame2" height="100%" src="Materials AU Stocked.htm" scrolling="yes" frameborder="1"></td>
    </tr>
</table>

Answer 1

You can do this using position: absolute with your second iframe and specifying top, bottom, left and right.

This requires your #header and first iframe have a fixed height.

Note I’ve put in some external websites in the iframe src for testing purposes. Replace these with your desired html pages.

HTML

<div id="header">
    <h1>Header</h1>
</div>
<iframe id="iFrame1" name="iFrame1" src="http://yahoo.com"></iframe>
<div id="iFrame2Container">
    <iframe id="iFrame2" name="iFrame2" src="http://yahoo.com"></iframe>
</div>

CSS

* {
    margin: 0;
    padding: 0
}
html, body {
    height: 100%;
    width: 100%;
    overflow: hidden
}
#header {
    border-bottom: 1px solid #000;
    height: 19px;
}

#iFrame1 {
    height: 80px;
    width: 100%;
    border: none;
    overflow: hidden;
}
#iFrame2Container {
    position: absolute;
    top: 100px;
    left: 0px;
    bottom: 0px;
    right: 0px;
}
#iFrame2 {
    width: 100%;
    height: 100%;
    border: none;
}

Demo

A few extra things that I noticed in your code

• You shouldn’t use tables for layout
• You shouldn’t put spaces in your html filename
  • Rename Materials AU Stocked Header.htm to somethin like Materials-AU-Stocked Header.htm
• Close tags you open
  • <iframe> needs </iframe> after it