kirikaza/gist:3d0fea138fbfb862bb78

## gistfile1.html
<!DOCTYPE html>
<html>
<head>
  <style>
    * { font-size: 20px; }
    html, body { margin: 0; padding: 0; }
  </style>
  <!-- meta name="viewport" content=""/ -->
</head>
<body>
<script>
function viewport() {
  var viewport = document.getElementsByTagName('meta')[0];
  if (viewport) {
    viewport.content = 'width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no';
  } else {
    var viewport = document.createElement('meta');
    viewport.name = 'viewport';
    viewport.content = 'width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no';
    var head = document.getElementsByTagName('head')[0];
    head.appendChild(viewport);
  }
}
</script>
<br/><br/>
<p>text text text, a lot of text, more and more</p>
<a onclick="viewport(); return false">
<div style="width:310px; height:310px; background-color:#69C; border:solid 5px #F0C;"></div>
</a>
</body>
</html>
	<!DOCTYPE html>
	<html>
	<head>
	<style>
	* { font-size: 20px; }
	html, body { margin: 0; padding: 0; }
	</style>
	<!-- meta name="viewport" content=""/ -->
	</head>
	<body>
	<script>
	function viewport() {
	var viewport = document.getElementsByTagName('meta')[0];
	if (viewport) {
	viewport.content = 'width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no';
	} else {
	var viewport = document.createElement('meta');
	viewport.name = 'viewport';
	viewport.content = 'width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no';
	var head = document.getElementsByTagName('head')[0];
	head.appendChild(viewport);
	}
	}
	</script>
	<br/><br/>
	<p>text text text, a lot of text, more and more</p>
	<a onclick="viewport(); return false">
	<div style="width:310px; height:310px; background-color:#69C; border:solid 5px #F0C;"></div>
	</a>
	</body>
	</html>