Walk through all elements on a form

In some cases it is required to set all attributes on a form to disabled or do some other logic like checking which attribute has been changed. To do this you do need to walk through each attribute of the CRM form. My fellow MVP Mitch Milam has posted the technique to do this more than a year ago:
http://blogs.infinite-x.net/2007/11/21/disabling-all-fields-on-a-crm-form/

The most important piece of this code is:

var iLen = crmForm.all.length;
for (i = 0; i < iLen; i++)
{
o = crmForm.all[i];
switch (o.tagName)
{
case "INPUT":
case "SELECT":
case "TEXTAREA":
case "IMG":
case "IFRAME":
if (o.id != "leadqualitycode")
{
o.disabled = true;
}
break;
default:
break;
}
}

This example does set all attributes to disabled, but another option would be to replace the o.disabled = true; line with something like:

if (o.IsDirty)
{
alert("The value of " + o.name + " has changed.");
}

This allows you to determine which attributes have been changed on the form.