Custom alert using Javascript

Question

How can I create a custom alert function in Javascript?

Answer 1

You can override the existing alert function, which exists on the window object:

window.alert = function (message) {
  // Do something with message
};

Answer 2

This is the solution I came up with. I wrote a generic function to create a jQueryUI dialog. If you wanted, you could override the default alert function using Matt's suggestion: window.alert = alert2;

// Generic self-contained jQueryUI alternative to
// the browser's default JavaScript alert method.
// The only prerequisite is to include jQuery & jQueryUI
// This method automatically creates/destroys the container div
// params:
//     message = message to display
//     title = the title to display on the alert
//     buttonText = the text to display on the button which closes the alert
function alert2(message, title, buttonText) {

    buttonText = (buttonText == undefined) ? "Ok" : buttonText;
    title = (title == undefined) ? "The page says:" : title;

    var div = $('<div>');
    div.html(message);
    div.attr('title', title);
    div.dialog({
        autoOpen: true,
        modal: true,
        draggable: false,
        resizable: false,
        buttons: [{
            text: buttonText,
            click: function () {
                $(this).dialog("close");
                div.remove();
            }
        }]
    });
}