update IE documentation on home page

diff --git a/docs/index.html b/docs/index.html
index b21c5c2..2a14b3c 100644 (file)
--- a/docs/index.html
+++ b/docs/index.html
@@ -361,21 +361,26 @@
 
       <p>The dygraphs library relies heavily on the HTML5 <code>&lt;canvas&gt;</code> tag, which Microsoft Internet Explorer did not traditionally support. To use Microsoft's native canvas implementation in IE9, you need to set an HTML5 doctype on your page:</p>
 
-      <pre>
-      &lt;!DOCTYPE html&gt; 
-      </pre>
+<pre>
+&lt;!DOCTYPE html&gt;
+</pre>
 
       <p>When IE9 is in HTML5 mode, dygraphs works just like in other modern browsers.</p>
 
-      <p>If you want to support previous versions of Internet Explorer (IE6&ndash;IE8), you'll need to include the <a href="http://code.google.com/p/explorercanvas/">excanvas</a> library, which emulates the <code>&lt;canvas&gt;</code> tag using VML. You can add excanvas by including this snippet:</p>
+      <p>If you want to support previous versions of Internet Explorer (IE6&ndash;IE8), you'll need to include the <a href="http://code.google.com/p/explorercanvas/">excanvas</a> library, which emulates the <code>&lt;canvas&gt;</code> tag using VML. You can add excanvas by including the following snippet:</p>
 
 <pre>
-&lt;head&gt;
-  &lt;!--[if IE]&gt;&lt;script src="excanvas.js"&gt;&lt;/script&gt;&lt;![endif]--&gt;
-&lt;/head&gt;
+&lt;!DOCTYPE html&gt; 
+&lt;html&gt;
+  &lt;head&gt;
+    &lt;meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7; IE=EmulateIE9"&gt; 
+    &lt;!--[if IE]&gt;&lt;script src="path/to/excanvas.js"&gt;&lt;/script&gt;&lt;![endif]--&gt;
+  &lt;/head&gt;
 </pre>
 
-    <p>While this sounds like it would be slow, it works well in practice for most charts.</p>
+<p>(This is surprisingly tricky because the HTML5 doctype breaks excanvas in IE8. See <a href="https://groups.google.com/group/dygraphs-users/browse_thread/thread/c60709e04bc7fe5f#">this discussion</a> for details.)</p>
+
+    <p>While VML emulation sounds like it would be slow, it works well in practice for most charts.</p>
 
     <p>One common gotcha to look out for: make sure you don't have any trailing commas in parameter lists, e.g.</p>