How to detect input-text pressed key on javascript

I have this simple document:

   <!DOCTYPE html>
      <html>
        <body>
        <input id="mytext" onkeypress="myfun(e)"></input>
        <p id="demo"></p>
        <script> function myfun(e){ 
                if(e.keyCode==13) alert('Enter Key Pressed');}
        });
        </script>
        </body>
      </html>

what I want is: when user press enter key on mytext, show an alert to inform the user like this message : Enter Key Pressed

I did every thing like above, But it doesn't work and no any alert is shown when enter pressed on mytext.

Help Please!..

Solution

Your code works when you replace myfun(e) with myfun(event). I also corrected some syntactical errors.

 <html>
    <body>
        <input id="mytext" onkeypress="myfun(event)"></input>
        <p id="demo"></p>
        <script> 
            function myfun(e){ 
                    if(e.keyCode==13) alert('Enter Key Pressed');
            };
        </script>
    </body>
</html>