Check all checkboxes on a website that only allows you do to it manually

So I had this issue the other day.. In 2009 some websites still have manual checkboxes.. Yeeks

You want to select all checkboxes on a website and it only allows you to do it manually?:D

Install firefox if you don't already have it. Install firebug.

NOTE FROM 2016:  You can use almost any browser these days since they all seem to have copied the "inspect element" thing from Firebug.

Open firebug..
type the following in the console:

function check_all_in_document(doc)
{
	var c = new Array();
	c = doc.getElementsByTagName('input');
	for (var i = 0; i < c.length; i++)
	{
		if (c[i].type == 'checkbox')
		{
			c[i].checked = true;
		}
	}
}
function checkem()
{
	check_all_in_document(window.document);
	for (var j = 0; j < window.frames.length; j++)
	{
		check_all_in_document(window.frames[j].document);
	}
}

click run:)
have fun!
checkem();