<!DOCTYPE html>
<html>
<head>
<script>
onerror = handleErr;
var txt = "";
function handleErr(msg, url, l) {
txt = "There was an error on this page.\n\n";
txt += "Error: " + msg + "\n";
txt += "URL: " + url + "\n";
txt += "Line: " + l + "\n\n";
txt += "Click OK to continue.\n\n";
alert(txt);
return true;
}
function message() {
adddlert("Welcome guest!");
}
</script>
</head>
<body>
<input type="button" value="View message" onclick="message()" />
</body>
</html>