index.html

<!DOCTYPE html>
<html>
<head>
<title>Expressionizr</title>
<link rel="icon" type="image/png" href="logo.png" />
<title>Expressionizr</title>
<script type="text/x-mathjax-config">
  MathJax.Hub.Config({tex2jax: {inlineMath: [['$','$'], ['\\(','\\)']]}});
</script>
<script type="text/javascript"
  src="mathjax.js">
</script>
<script type="text/javascript">
	function alertFilename() {
		var thisfile = document.getElementById('thefile');
		window.open(thisfile.value.substring(12)+'.html');
	}
</script>
<link rel="stylesheet" href="buttons.css">
</head>
<body bgcolor=#ddd>
<a href="index.html"><h1><font size="5000" color=#1d908a>
$\ \ \Huge{e}\Large{\mathrm{xpressionizr}}$
</font></h1></a>
<br><br>
<form onsubmit="javascript:alertFilename()">
<blockquote><input type="file" id="thefile" name="upfile" class="bluebtn"><input type="submit" name="Submit" class="greenbtn"></blockquote>
</form>
</body>
</html>