Question

while using document cookie

<script typ="text/javascript"> 
        document.domain="example.com"; 
</script>

I got an error.i don’t know the exact problem.

Error: uncaught exception: [Exception… “Illegal document.domain
value” code: “1009” nsresult: “0x805303f1
(NS_ERROR_DOM_BAD_DOCUMENT_DOMAIN)” location: “”]

Answer 1

According to the HTML spec, document.domain is read-only. However, Firefox allows setting it to a superdomain:

https://developer.mozilla.org/en/document.domain

In the DOM HTML specification, this property is listed as being
read-only. However, Mozilla will let you set it to a superdomain of
the current value, constrained by its base domain. For example, on
developer.mozilla.org it is possible to set it to “mozilla.org” but
not “mozilla.com” or “org”.

The error you’re getting clearly states that you’re making an illegal domain assignment.

You mention cookies in your question. If you’re trying to set the domain part of a cookie, setting document.domain has nothing to do with it. You need to provide a domain parameter as part of the cookie string that you’re assigning:

document.cookie = "foo=bar;domain=example.com";

More info here: https://developer.mozilla.org/en/DOM/document.cookie