$(document).ready(function(){
$('#TextBoxId').keypress(function(e){
if(e.keyCode==13)
$('#linkadd').click();
});
});

1. Replace the button with a submit
2. Be progressive, make sure you have a server side version
3. Bind your JavaScript to the submit handler of the form, not the click handler of the button

Pressing enter in the field will trigger form submission, and the submit handler will fire.

This should do it, I am using jQuery you can write plain javascript.
Replace sendMessage() with your functionality.

$('#addLinks').keypress(function(e) {
if (e.which == 13) {
sendMessage();
e.preventDefault();
}
});

First of all add jquery library file jquery and call it in your html head.

and then Use jquery based code...

$("#id_of_textbox").keyup(function(event){
if(event.keyCode == 13){
$("#id_of_button").click();
}
});

You could add an event handler to your input like so:

document.getElementById('addLinks').onkeypress=function(e){
if(e.keyCode==13){
document.getElementById('linkadd').click();
}
}

There are a js-free solution.

Set type=submit to the button you'd like to be default and type=button to other buttons. Now in the form below you can hit Enter in any input fields, and the Render button will work (despite the fact it is the second button in the form).

Example:

    <button id='close_renderer_button' class='btn btn-success'
title='Перейти к редактированию программы'
type=button>
<span class='glyphicon glyphicon-edit'> </span> Edit program
</button>
<button id='render_button' class='btn btn-primary'
title='Построить фрактал'
type=submit
formaction='javascript:alert("Bingo!");'>
<span class='glyphicon glyphicon-send'> </span> Render
</button>

Tested in FF24 and Chrome 35 (formaction is html5 feature, but type is not).

It works when input type="button" is replaced with input type="submit" for the default button which needs to be triggered.

Based on some previous answers, I came up with this:

<form>
<button id='but' type='submit'>do not click me</button>
<input type='text' placeholder='press enter'>
</form>


$('#but').click(function(e) {
alert('button press');
e.preventDefault();
});

Take a look at the Fiddle

EDIT: If you dont want to add additional html elements, you can do this with JS only:

    $("input").keyup(function(event) {
if (event.keyCode === 13) {
$("button").click();
}
});

I am using a kendo button. This worked for me.

<div class="form-group" id="indexform">
<div class="col-md-8">
<div class="row">
<b>Search By Customer Name/ Customer Number:</b>
@Html.TextBox("txtSearchString", null, new { style = "width:400px" , autofocus = "autofocus" })
@(Html.Kendo().Button()
.Name("btnSearch")
.HtmlAttributes(new { type = "button", @class = "k-primary" })
.Content("Search")
.Events(ev => ev.Click("onClick")))
</div>
</div>
</div>
<script>
var validator = $("#indexform").kendoValidator().data("kendoValidator"),
status = $(".status");
$("#indexform").keyup(function (event) {
if (event.keyCode == 13) {
$("#btnSearch").click();
}
});
</script>

It is, ^yeah, 2021. And I believe this still holds true.

DO NOT USE keypress

1. keypress event is not triggered when the user presses Tab0, such as Tab, Caps Lock, Delete, Backspace, Escape, left & right Shift, function keys(F1 - F12).

keypress event _{Mozilla Developer Network}

The keypress event is fired when a key is pressed down, and that key normally produces a character value. Use input instead.

2. It has been deprecated.

keypress event _{UI Events (W3C working draft published on November 8, 2018.)}

• NOTE | The keypress event is traditionally associated with detecting a character value rather than a physical key, and might not be available on all keys in some configurations.
• WARNING | The keypress event type is defined in this specification for reference and completeness, but this specification deprecates the use of this event type. When in editing contexts, authors can subscribe to the beforeinput event instead.

DO NOT USE KeyboardEvent.keyCode

1. It has been deprecated.

KeyboardEvent.keyCode _{Mozilla Developer Network}

Deprecated | This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

What should I use then? (The good practice)

// Make sure this code gets executed after the DOM is loaded.
document.querySelector("#addLinks").addEventListener("keyup", event => {
if(event.key !== "Enter") return; // Use `.key` instead.
document.querySelector("#linkadd").click(); // Things you want to do.
event.preventDefault(); // No need to `return false;`.
});

I found w3schools.com howto, their try me page is at the following.

https://www.w3schools.com/howto/tryit.asp?filename=tryhow_js_trigger_button_enter

This worked in my regular browser but did not work in my php app which uses the built in php browser.

After toying a bit I came up with the following pure JavaScript alternative that works for my situation and should work in every other situation:

    function checkForEnterKey(){
if (event.keyCode === 13) {
event.preventDefault();
document.getElementById("myBtn").click();
}
}


function buttonClickEvent()
{
alert('The button has been clicked!');
}

HTML Press the enter key inside the textbox to activate the button.

    <br />
<input id="myInput" onkeyup="checkForEnterKey(this.value)">
<br />
<button id="myBtn" onclick="buttonClickEvent()">Button</button>

<input type="text" id="input_id" />


$('#input_id').keydown(function (event) {
if (event.keyCode == 13) {
// Call your function here or add code here
}
});

Do not use Javascript for this solution!!!

Modern HTML browsers today (and in the past) automatically submit the first form submit button they find when the ENTER/RETURN key is pressed by a user. NO JAVASCRIPT NEEDED! Browsers have worked this way for nearly 20 years but new web developers have not bothered to learn about it.

If you have multiple submit buttons in a web page or want more control, pressing the ENTER/RETURN keys will trigger submission of form data when any form field control in the web page that is associated with a submit type button or input has focus by the user, the autofocus attribute is set on any form field/button/input, or when the user tab's into any form field. The submit button for that field will then trigger when the ENTER/RETURN key is pressed. Otherwise, as mentioned above, pressing ENTER or RETURN on the keyboard automatically triggers the first available submit button for that form in the page.

So, instead of JavaScripting this, an easier solution is to just add tabindex=0 on any of your form fields or submit buttons inside a form element then autofocus on the first input control or submit button. Tabindex=0 assigns that input to the page's list of indexed tab order page items, and autofocus shifts focus to any of your form fields, triggering any submit button to respond to the ENTER/RETURN key command. The user can now press "ENTER" on their keyboard to submit the form at any point they like. This also has the advantage that the first form field is focused on and ready for data by the user. An example below:

<form id="buttonform2" name="buttonform2" action="#" method="get" role="form">
<label for="username1">Username</label>
<input type="text" id="username1" name="username" value="" size="20" maxlength="20" title="Username" tabindex="0" autofocus="autofocus" />
<label for="password1">Password</label>
<input type="password" id="password1" name="password" size="20" maxlength="20" value="" title="Password" tabindex="0" role="textbox" aria-label="Password" />
<button id="button2" name="button2" type="submit" value="submit" form="buttonform2" title="Submit" tabindex="0" role="button" aria-label="Submit">Submit</button>
</form>

Stop scripting everything! The browsers have had this native ability for almost 20 years!!

Using pure HTML form:

<form class="my-form" action="javascript:myFunction();">
<button>Submit</button>
</form>

By default, browsers will interpret Enter as submitting a form. <button> by default is type "submit" and accesses whatever is located in the form's action attribute (overridden if button's formaction is present). In this case for simplicity I use a javascript function with the javascript: pseudo-protocol, but it could be javascript event listener or a GET/POST method as in normal forms.