SP.UI.Status Class

<asp:Content ID="Main" ContentPlaceHolderID="PlaceHolderMain" runat="server">
<script type="text/ecmascript" language="ecmascript">

var statusId = '';
var notifyId = '';

function AddNotification() {
    notifyId = SP.UI.Notify.addNotification("Hello World!", true);
}

function RemoveNotification() {
    SP.UI.Notify.removeNotification(notifyId);
    notifyId  = '';
}

function AddStatus() {
    statusId = SP.UI.Status.addStatus("Status good!");
    SP.UI.Status.setStatusPriColor(statusId, 'red');
}

function RemoveLastStatus() {
    SP.UI.Status.removeStatus(statusId);
    statusId = '';
}

function RemoveAllStatus() {
    SP.UI.Status.removeAllStatus(true);
}

</script>

    <input id="Button1" type="button" value="Add Notification" onclick="AddNotification()" />
    <input id="Button2" type="button" value="Remove Notification" onclick="RemoveNotification()" />
    <p></p>
    <input id="Button3" type="button" value="Add Status" onclick="AddStatus()" />
    <input id="Button4" type="button" value="Remove Last Status" onclick="RemoveLastStatus()" />
    <input id="Button5" type="button" value="Remove All Status" onclick="RemoveAllStatus()" />

</asp:Content>