diff --git a/code/IFramePage.php b/code/IFramePage.php
index 36a30ff..e2826d0 100644
--- a/code/IFramePage.php
+++ b/code/IFramePage.php
@@ -1,49 +1,86 @@
 <?php
+/**
+ * Iframe page type embeds an iframe of URL of choice into the page.
+ * CMS editor can choose width, height, or set it to attempt automatic size configuration.
+ */
 
 class IFramePage extends Page {
 	static $db = array(
-		'IFrameUrl' => 'Text',
-		'DynamicHeight' => 'Boolean',
-		'FixedHeight' => 'Int',
+		'IFrameURL' => 'Text',
+		'AutoHeight' => 'Boolean(1)',
+		'AutoWidth' => 'Boolean(1)',
+		'FixedHeight' => 'Int(500)',
+		'FixedWidth' => 'Int(0)',
 		'AlternateContent' => 'HTMLText',
 		'BottomContent' => 'HTMLText'
 	);
+
+	static $defaults = array(
+		'AutoHeight' => '1',
+		'AutoWidth' => '1',
+		'FixedHeight' => '500',
+		'FixedWidth' => '0'
+	);
+
+	static $description = 'Embeds an iframe into the body of the page.';
 	
 	function getCMSFields() {
 		$fields = parent::getCMSFields();
 
 		$fields->removeFieldFromTab('Root.Main', 'Content');
-		$fields->addFieldToTab('Root.Main', new TextField('IFrameUrl', 'IFrame URL'));
-		$fields->addFieldToTab('Root.Main', new CheckboxField('DynamicHeight', 'Dynamically resize the IFrame height (this doesn\'t work if IFrame URL is on a different domain)'));
-		$fields->addFieldToTab('Root.Main', new NumericField('FixedHeight', 'Fixed Height (in pixels)'));
-		$fields->addFieldToTab('Root.Main', new HtmlEditorField('Content', 'Content (appears above IFrame)'));
-		$fields->addFieldToTab('Root.Main', new HtmlEditorField('BottomContent', 'Content (appears below IFrame)'));
-		$fields->addFieldToTab('Root.Main', new HtmlEditorField('AlternateContent', 'Alternate Content (appears when user has IFrames disabled)'));
+		$fields->addFieldToTab('Root.Main', $url = new TextField('IFrameURL', 'Iframe URL'));
+		$url->setRightTitle('Can be absolute (<em>http://silverstripe.com</em>) or relative to this site (<em>about-us</em>).');
+		$fields->addFieldToTab('Root.Main', new CheckboxField('AutoHeight', 'Auto height (only works with same domain URLs)'));
+		$fields->addFieldToTab('Root.Main', new CheckboxField('AutoWidth', 'Auto width (100% of the available space)'));
+		$fields->addFieldToTab('Root.Main', new NumericField('FixedHeight', 'Fixed height (in pixels)'));
+		$fields->addFieldToTab('Root.Main', new NumericField('FixedWidth', 'Fixed width (in pixels)'));
+		$fields->addFieldToTab('Root.Main', new HtmlEditorField('Content', 'Content (appears above iframe)'));
+		$fields->addFieldToTab('Root.Main', new HtmlEditorField('BottomContent', 'Content (appears below iframe)'));
+		$fields->addFieldToTab('Root.Main', new HtmlEditorField('AlternateContent', 'Alternate Content (appears when user has iframes disabled)'));
 
 		return $fields;
 	}
+
+	/**
+	 * Compute class from the size parameters.
+	 */
+	function getClass() {
+		$class = '';
+		if ($this->AutoHeight) {
+			$class .= 'iframepage-height-auto';
+		}
+
+		return $class;
+	}
+
+	/**
+	 * Compute style from the size parameters.
+	 */
+	function getStyle() {
+		$style = '';
+
+		// Always add fixed height as a fallback if autosetting or JS fails.
+		$height = $this->FixedHeight;
+		if (!$height) $height = 800;
+		$style .= "height: {$height}px; ";
+
+		if ($this->AutoWidth) {
+			$style .= "width: 100%; ";
+		}
+		else if ($this->FixedWidth) {
+			$style .= "width: {$this->FixedWidth}px; ";
+		}
+
+		return $style;
+	}
 }
 
 class IFramePage_Controller extends Page_Controller {
 	function init() {
 		parent::init();
 
-		if ($this->DynamicHeight) {
-			Requirements::customScript(<<<SCRIPT
-
-				if (typeof jQuery!=='undefined') {
-					jQuery(function($) {
-						var iframe = $('iframe.iframeautosize');
-						iframe.load(function() {
-							var iframeSize = $(iframe[0].contentWindow.document.body).height();
-							iframeSize = (parseInt(iframeSize)+100)+'px';
-							iframe.attr('height', iframeSize);
-						});
-					});
-				}
-
-SCRIPT
-			);
+		if ($this->IFrameURL) {
+			Requirements::javascript('iframe/javascript/iframe_page.js');
 		}
 	}
 }
diff --git a/javascript/iframe_page.js b/javascript/iframe_page.js
new file mode 100644
index 0000000..aca41b5
--- /dev/null
+++ b/javascript/iframe_page.js
@@ -0,0 +1,34 @@
+if (typeof jQuery!=='undefined') {
+	(function($) {
+		var iframe = $('#Iframepage-iframe');
+		var loading = $('#Iframepage-loading');
+
+		// Add not-ready marker for third party use.
+		iframe.addClass('iframepage-not-ready');
+		// Show loading message
+		iframe.hide();
+		loading.show();
+
+		$(function() {
+			iframe.load(function() {
+				// Iframe content has been loaded
+				loading.hide();
+				iframe.show();
+
+				if (iframe.hasClass('iframepage-height-auto')===true) {
+					// Try to set the height to the height of the iframe content (only possible if it is the same domain)
+					try {
+						var iframeInsideSize = $(iframe[0].contentWindow.document.body).height();
+						iframe.css('height', (parseInt(iframeInsideSize)+100)+'px');
+					}
+					catch(e) {
+						// Failed to set the height, we fall back to default css height.
+					}
+				}
+
+				// Finally, remove the marker
+				iframe.removeClass('iframepage-not-ready');
+			});
+		});
+	})(jQuery);
+}
diff --git a/templates/Layout/IFramePage.ss b/templates/Layout/IFramePage.ss
index 201c749..1c3fbe5 100644
--- a/templates/Layout/IFramePage.ss
+++ b/templates/Layout/IFramePage.ss
@@ -2,10 +2,9 @@
 	<h2>$Title</h2>
 	
 	$Content
-	<% if DynamicHeight %>
-		<iframe src="$IFrameUrl" class="iframeautosize" style="width: 100%;">$AlternateContent</iframe>
-	<% else %>
-		<iframe src="$IFrameUrl" style="width: 100%; height: {$FixedHeight}px;">$AlternateContent</iframe>
+	<% if IFrameURL %>
+		<span id="Iframepage-loading" style="display: none;">External content is loading...</span>
+		<iframe id="Iframepage-iframe" style="$Style" src="$IFrameURL" class="$Class">$AlternateContent</iframe>
 	<% end_if %>
 	$BottomContent
 </div>
diff --git a/tests/IFramePageTest.php b/tests/IFramePageTest.php
new file mode 100644
index 0000000..9a407e9
--- /dev/null
+++ b/tests/IFramePageTest.php
@@ -0,0 +1,36 @@
+<?php
+
+class IFramePageTest extends SapphireTest {
+	function testGetClass() {
+		$iframe = new IFramePage();
+		$iframe->AutoHeight = 1;
+		$iframe->getClass();
+
+		$this->assertContains('iframepage-height-auto', $iframe->getClass());
+
+		$iframe->AutoHeight = 0;
+		$iframe->getClass();
+
+		$this->assertNotContains('iframepage-height-auto', $iframe->getClass());
+	}
+
+	function testGetStyle() {
+		$iframe = new IFramePage();
+
+		$iframe->FixedHeight = 0;
+		$iframe->getStyle();
+		$this->assertContains('height: 800px', $iframe->getStyle(), 'Height defaults to 800 if not set.');
+
+		$iframe->FixedHeight = 100;
+		$iframe->getStyle();
+		$this->assertContains('height: 100px', $iframe->getStyle(), 'Fixed height is settable');
+
+		$iframe->AutoWidth = 1;
+		$iframe->FixedWidth = '200';
+		$this->assertContains('width: 100%', $iframe->getStyle(), 'Auto width overrides fixed width');
+
+		$iframe->AutoWidth = 0;
+		$iframe->FixedWidth = '200';
+		$this->assertContains('width: 200px', $iframe->getStyle(), 'Fixed width is settable');
+	}
+}