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<html><body><form> <select id="mySelect" size="4"> <option>Apple</option> <option>Pear</option> <option>Banana</option> <option>Orange</option> </select></form><p>Click the button to allow multiple selection (meaning that you can select more than one option in the drop-down list).</p><button type="button" onclick="myFunction()">Try it</button><p><b>Tip:</b> Hold Ctrl or Shift to select more than one option.</p><p id="demo"></p><script>function myFunction() { document.getElementById("mySelect").multiple = true; document.getElementById("demo").innerHTML = "You can now select multiple options.";}</script></body></html>