jScript confirm on navigate away when fields are dirty, multibrowser implementation?

I've been trying to implement the jquery.safetynet plug-in but I've been having difficulties getting it to work with check boxes and across multiple browsers. (Read: It must be ie6 compatible)

I've decided to give up on this implementation even though I really like it.

Do you have a good r开发者_如何学Pythonecommendation for a dirty field check and prompt for: navigate away, refresh, browser close?

Thanks!

use window.onbeforeunload to be notified when the page unloads. To check if anything is dirty within a form, you can query for all input, selects and see if the values are different than when the page was loaded.

I copy pasted this from the web to check if any values in a form are modified

window.onbeforeunload = function(e) {
   if (isFormModified(document.getElementById('form-id-goes-here'))) {
     return e.returnValue = "You have unsaved data in your form";
   }
}

function isFormModified(oForm)
{
    var el, opt, hasDefault, i = 0, j;
    while (el = oForm.elements[i++]) {
        switch (el.type) {
            case 'text' :
            case 'textarea' :
            case 'hidden' :
                if (!/^\s*$/.test(el.value) && el.value != el.defaultValue) {
                    return true;
                }
                break;
            case 'checkbox' :
            case 'radio' :
                if (el.checked != el.defaultChecked) {
                    return true;
                }
                break;
            case 'select-one' :
            case 'select-multiple' :
                j = 0, hasDefault = false;
                while (opt = el.options[j++]) {
                    if (opt.defaultSelected) { 
                        hasDefault = true; 
                    }
                }
                j = hasDefault ? 0 : 1;
                while (opt = el.options[j++]) {
                    if (opt.selected != opt.defaultSelected) {
                      return true;
                    }
                }

                break;
        }
    }
    return false;
}