DONT ADD ANYTHING HERE!

  1. The select element represents a control that provides a menu of options
  2. An id attribute allows association witha a label
  3. A name attribute allows submittion of data to server
  4. Each menu option is defined by an option element nested inside the select
  5. value
    1. Each option element should have a value attribute containing the data value to submit to the server when that option is selected
    2. If no value attribute is included, the value defaults to the text contained inside the element
  6. selected
    Including a selected attribute on an option element makes it selected by default
  7. optgroup
    1. option elements may be included inside optgroup to create separate groups of options
    2. hr elements may also be included as separators to add visual breaks
  8. multiple
    Allows multiple options to be selected
  9. size
    Specifies how may options shown at once

Example

HTML

<form id="form_one">
    <label for="pet-select">Choose a pet:</label>

    <select name="param2" id="pet-select">
        <option value="">--Please choose an option--</option>
        <option value="dog">Dog</option>
        <option value="cat">Cat</option>
        <option value="hamster">Hamster</option>
        <option value="parrot">Parrot</option>
        <option value="spider">Spider</option>
        <option value="goldfish">Goldfish</option>
    </select>
    <input type="hidden" value="You chose " name="param1">
    <input type="submit">
</form>
<div>
    <output id="selected"></output>
</div>
JavaScript 
// form
async function sendData() {

    const formData = new FormData(form_one);

    try {
    const response = await fetch("https://php.tomgdow.com", {
        method: "POST",
        body: formData
    });

    let result = await response.text();
    console.log(result);
    let responseArray = result.split('&');
    document.getElementById('selected').value = responseArray[0];
    document.getElementById('selected').value += responseArray[1];

    } catch (e) {
    console.error(e);
    }
}

document.getElementById('form_one').addEventListener('submit', function (event) {

    event.preventDefault();

    sendData();

});

Browser

References

MDN: The HTML Select element
W3C Select