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<body>
<p>A form with a URL field that must start with http:// or https:// followed by at least one character:</p>
<form action="https://www.w3schools.com/action_page.php">
Homepage: <input type="url" name="website" pattern="https?://.+" title="Include http://">
<input type="submit">
</form>
<p><strong>Note:</strong> The pattern attribute of the input tag is not supported in Internet Explorer 9 and earlier versions.</p>
</body>
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