How to Detect Enter key in Firefox?

Question

I am trying to detect Enter Key. Here is my code.

HTML

<input name="txtTest"  type="text" id="txtTest" onkeyup="CheckKey()"/>

Javascript

function CheckKey()
{
    var e = window.event;
    var code = e.keyCode ? e.keyCode : e.which;
    if(code === 13)
    {
      alert("You press Enter key.");
    }            
}

This code is working in other browsers but not in Firefox Why? Here is jsFiddle

Please provide answers using javascript only.

Answer 1

I believe you have to pass the event object to the handler:

<input name="txtTest"  type="text" id="txtTest" onkeyup="CheckKey(event)"/>
<!--                                            passes event object ^   -->

function CheckKey(e) //receives event object as parameter
{
   var code = e.keyCode ? e.keyCode : e.which;
   if(code === 13)
   {
       alert("You press Enter key.");
   }
}

Fiddle

Answer 2

You should separate JavaScript code from HTML.

Try something like this - key should work on all browsers:

<input type="text" id="txtTest" onkeyup="CheckKey(e)"/>

function CheckKey(e) {
   var key = e.charCode ? e.charCode : e.keyCode ? e.keyCode : 0;
   if(key === 13)
   {
       alert("You press Enter key.");
   }
}

Or as suggested with jQuery (separated JavaScript code from HTML) - use event.which:

   <!--HTML file e.g. index.html-->
   <input type="text" id="txtTest" />

    //JavaScript file e.g. script.js - you have to include that script in your HTML file
    $(function(){
      $('#txtTest').on('keyup', function(e){
          if(e.which === 13)
          {
            alert("You press Enter key.");
          }
      });
    });