error.js

这是《JavaScript学习源代码》一书的源代码

// declare an error-handling function
window.onerror = errorhandler;

// define the error-handling function
function errorhandler( msg, url, ln )
{              
  alert("Error: "+msg+"\nIn File:"+url+"\nAt Line:"+ln);
  return true;    // tell the browser it's been handled                                        
}

// This is a deliberate mistake            
document.getElementById("btn").value = "myButton";