Introductory HTML exercise I have started learning HTML. Here is one of the very basic HTML pages I have written. I would appreciate advice about how to write code especially regarding indentation.

&lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt; 
&lt;html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"&gt; 
&lt;head&gt;
&lt;title&gt; Checking Different Headings | Isnt it fun?&lt;/title&gt;
&lt;/head&gt;

&lt;body&gt;
&lt;h1&gt;  This is big&lt;/h1&gt;
&lt;h2&gt;  This is also good &lt;/h2&gt;
&lt;h3&gt;  This is also good &lt;/h3&gt;
&lt;h4&gt;  This is also good  &lt;/h4&gt;
&lt;h5&gt;  This is also good &lt;/h5&gt;
&lt;h6&gt;  This is small &lt;/h6&gt;
&lt;/body&gt;
&lt;/html&gt;
I start my intention in head and body.

&lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt; 
&lt;html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"&gt; 
&lt;head&gt;
    &lt;title&gt; Checking Different Headings | Isnt it fun?&lt;/title&gt;
&lt;/head&gt;

&lt;body&gt;
    &lt;h1&gt;This is big&lt;/h1&gt;
    &lt;h2&gt;This is also good&lt;/h2&gt;
    &lt;h3&gt;This is also good&lt;/h3&gt;
    &lt;h4&gt;This is also good &lt;/h4&gt;
    &lt;h5&gt;This is also good&lt;/h5&gt;
    &lt;h6&gt;This is small&lt;/h6&gt;
&lt;/body&gt;
&lt;/html&gt;


I also keep my tag tight–no spaces between text and tag.