I was working in HTML and had a div, and within that div, I had an ID and a Class named seventy for example with some attributes. This is simplified as to illustrate my question:

```
<?php

    $height = 'seventy';
?>

<div id="meter" class="<? echo $height;?> "></div>

```

This worked perfectly from my laptop running Xampp. When I run it on server 2003, running Xampp, the div tag closed early, and I got a simple textdisplay of ' "> ' after where the div went. So after messing around for a while I discovered that ' 

```
<?php

    $height = 'seventy';
?>

<div id="meter" class="<?php echo $height;?> "></div>

```

It worked. Can anyone give me some insight as to why sometimes you can shorthand the open tag and sometimes you can not. I am very novice, and this kind of thing intriges me.