df = {
	hideClass: 'hide',
	sourceOption: 'referral_source',
	
	init:function() {
		if (!document.getElementById || !document.createTextNode) { return; }
		df.source = document.getElementById(df.sourceOption);
		if (!df.source) { return; }
		df.sourceOpt = DOMhelp.closestSibling( df.source.parentNode.parentNode, 1);
		DOMhelp.cssjs('add', df.sourceOpt, df.hideClass);
		DOMhelp.addEvent(df.source, 'change', df.sourceChange, false);
	},
	sourceChange:function(e) {
		var t = DOMhelp.getTarget(e);
		var action = t.selectedIndex == 10 ? 'remove' : 'add';
		DOMhelp.cssjs(action, df.sourceOpt, df.hideClass);
		if (action == 'remove') {
			df.sourceOpt.getElementsByTagName('input')[0].focus();
		}
	}
}
DOMhelp.addEvent(window, 'load', df.init, false);