<!DOCTYPE html>
<html>
<body>

<form action="form_action.asp">
Text area:<br>
<textarea id="myTextarea" name="adr" required>
</textarea><br>
<input type="submit">
</form>

<p>Click the "Try it" button to find out if the text area must be filled out before submitting the form.</p>

<button onclick="myFunction()">Try it</button>

<p id="demo"></p>

<script>
function myFunction() {
    var x = document.getElementById("myTextarea").required;
    document.getElementById("demo").innerHTML = x;
}
</script>

</body>
</html>