<!DOCTYPE html>
<html>
<body>
<form target="_blank">
First name: <input type="text" name="fname" value="Donald"><br>
Last name: <input type="text" name="lname" value="Duck"><br>
<button id="myBtn" formaction="demo_form_method.asp" formmethod="get" type="submit">Submit</button>
</form>
<p>Click the "Try it" button to change the value of the formmethod and formaction attributes of the submit button in the form above.</p>
<p><b>Note:</b> Click on the "Submit" button before and after you have clicked on the "Try it" button, to see the effect!</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
document.getElementById("myBtn").formMethod = "post";
document.getElementById("myBtn").formAction = "demo_form_method_post.asp";
document.getElementById("demo").innerHTML = "The value of formaction and formmethod was changed.";
}
</script>
</body>
</html>