function activate_interface() {
     var data_div = document.getElementById("data");
	data_div.className = "non_active"; 
     var int_div = document.getElementById("interface");
	int_div.className = "active"; 
}
	/*
	 * cssjs
	 * written by Christian Heilmann (http://icant.co.uk)
	 * eases the dynamic application of CSS classes via DOM
	 * parameters: action a, object o and class names c1 and c2 (c2 optional)
	 * actions: swap exchanges c1 and c2 in object o
	 *			add adds class c1 to object o
	 *			remove removes class c1 from object o
	 *			check tests if class c1 is applied to object o
	 * example:	cssjs('swap',document.getElementById('foo'),'bar','baz');
	 */
function flash_error() {
     var data_div = document.getElementById("data");
	data_div.className = "non_active"; 
     var int_div = document.getElementById("interface");
	int_div.className = "active"; 
}