function clear_input(action, object, value) {

	if(action == "focus" && object.value == value) {
		object.value = "";
	}
	if(action == "blur" && object.value == "") {
		object.value = value;
	}
}

function toggle_navi(action, id, id2, id3, id4) {

	if(action == "show") {
		var display = "block";
	}else{
		var display = "none";
	}

	if(id2 != "") {
		var navi2 = document.getElementById("mainnavi_" + id2);
		navi2.style.display = display;
	}
	if(id3 != "") {
		var navi3 = document.getElementById("mainnavi_" + id3);
		navi3.style.display = display;
	}
	if(id4 != "") {
		var navi4 = document.getElementById("mainnavi_" + id4);
		navi4.style.display = display;
	}

	var navi = document.getElementById("mainnavi_" + id);
	navi.style.display = display;
}