Tryit Editor v1.8

Source Code:

<html>
<body>
<h3>
This demonstrates a parser error:
</h3>

<script>
var xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
xmlDoc.async="false";
xmlDoc.validateOnParse="true";
xmlDoc.load("note_dtd_error.xml");

document.write("<br>Error Code: ");
document.write(xmlDoc.parseError.errorCode);
document.write("<br>Error Reason: ");
document.write(xmlDoc.parseError.reason);
document.write("<br>Error Line: ");
document.write(xmlDoc.parseError.line);
</script>

</body>
</html>

Result:

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