<!DOCTYPE html>
<html lang="cs">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Výběr s Datalist</title>
  <script>
    function validateInput(input) {
      const datalist = document.getElementById('fruit-list');
      const options = datalist.getElementsByTagName('option');
      const values = Array.from(options).map(option => option.value);

      if (!values.includes(input.value)) {
        input.value = ''; // Vymaže hodnotu, pokud není v datalistu
      }
    }
  </script>
</head>
<body>
  <form>
    <label for="fruit">Vyberte ovoce:</label>
    <input type="text" id="fruit" name="fruit" list="fruit-list" oninput="validateInput(this)">
    <datalist id="fruit-list">
      <option value="Jablko">
      <option value="Banán">
      <option value="Třešně">
      <option value="Datle">
    </datalist>
    <button type="submit">Odeslat</button>
  </form>
</body>
</html>