Tryit Editor v1.8

Source Code:
<!DOCTYPE html> <html> <head> <script src="../../ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"> </script> <script> $(document).ready(function(){ $("input").change(function(){ alert("The text has been changed."); }); }); </script> </head> <body> <input type="text"> <p>Write something in the input field, and then press enter or click outside the field.</p> </body> </html>
Result:
W3Schools.com - Try it yourself