This file demonstrates an image button that does not contain any "alt" text.
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html lang="en">
<head>
<title>alert 1.0/1.1.3</title>
</head>
<body>
<input type="image" name="submit" src="submit.jpg" />
</body>
</html>