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<html><body><h1>The select required attribute</h1><p>The required attribute specifies that the user is required to select a value before submitting the form:</p><form action="/action_page.php"> <label for="cars">Choose a car:</label> <select name="cars" id="cars" required> <option value="">None</option> <option value="volvo">Volvo</option> <option value="saab">Saab</option> <option value="mercedes">Mercedes</option> <option value="audi">Audi</option> </select> <br><br> <input type="submit" value="Submit"></form></body></html>