How can I use the values filled in form, On clicking submit button.

Question

I want to make a programme. But I am facing problem in it.
Please, answer with js code example.

Answer 1

<input type="text" id="test"value="1234">
<button onClick="test()">Test</button>
<script>
function test(){
var res=document.getElementById("test").value;
alert(res);
}
</script>