function show_hide(id) {
		obj = document.getElementById(id);
		if(typeof(obj) != 'object') return;
		if (obj.style.display == 'block'){
			obj.style.display = 'none';
		}
		else{
			obj.style.display = 'block';
		}
	}

	function plus_minus(id) {
		obj = document.getElementById(id);
		if(typeof(obj) != 'object') return;
		if (obj.src.indexOf('plus') == -1){
			obj.src = 'http://www.gnspy.org/_site/images/plus.gif';
		}
		else{
			obj.src = 'http://www.gnspy.org/_site/images/minus.gif';
		}
	}

	function show_hide2(id_1, id_2) {
		obj = document.getElementById(id_1);
		if(typeof(obj) != 'object') return;
		if (obj.style.display == 'block'){
			obj.style.display = 'none';
		}
		else{
			obj.style.display = 'block';
		}

		obj = document.getElementById(id_2);
		if(typeof(obj) != 'object') return;
		obj.style.display = 'none';
	}

	function hide(id) {
		obj = document.getElementById(id);
		if(typeof(obj) != 'object') return;
		
		obj.style.display = 'none';
	}

	function ajaxChangeSignal() {
		var obj = document.getElementById('layer_signal');
		var doc = document.body.getElementsByTagName('a');
		var cs = 'auto';

		if (document.body.style.cursor == 'wait') {
			cs = 'pointer';
			document.body.style.cursor = 'auto';
		} else {
			cs = 'wait';
			document.body.style.cursor = 'wait';
		}

		for (var i=0; i<doc.length; i++) {
			doc[i].style.cursor = cs;
		}
	}


	function ajaxRequest(url, layer) {
		var layer = (layer == null) ? 'layer_content' : layer;
		
		ajaxChangeSignal();

		new Ajax(url, {method: 'get', update: layer, onComplete: ajaxChangeSignal}).request();
	}