var MSG_TIMEOUT = 60 * 1000; // one minute

var DisplayMessage = Class.create();

DisplayMessage.prototype = {
    element: null,
    prev: null,

    initialize: function( element ) {
        this.element = element;
    },

    _msg : function( message, color ) {
        if ( this.element == null ) { return; }
        window.clearTimeout( this.prev );
        this.element.style.color = color;
        this.element.innerHTML = message;
        this.prev = window.setTimeout( this.clear , MSG_TIMEOUT );
    },

    message: function( message ) {
        this._msg( message, 'black' );
    },

    info: function( message ) {
        this._msg( message, 'blue' );
    },

    error: function( message ) {
        this._msg( message, 'red' );
    },

    clear: function() {
        if ( this.element == null ) { return; }
        this.element.style.color = 'black';
        this.element.innerHTML = '';
    }

}