1<form>
2    <input id="myInput" placeholder="Some text.." value="">
3    <input type="submit" id="myBtn" value="Submit">
4</form>
5
6<script>
7var input = document.getElementById("myInput");
8input.addEventListener("keyup", function(event) {
9    if (event.keyCode === 13) {
10        event.preventDefault();
11        document.getElementById("myBtn").click();
12    }
13});
14</script>
15

1$("#id_of_textbox").keyup(function(event) {
2    if (event.keyCode === 13) {
3        $("#id_of_button").click();
4    }
5});
6