关于js消息提示的案例

/** 
*消息构造  
*/  
function CLASS_MSN_MESSAGE(id,width,height,caption,title,message,url,target,action){  
    this.id     = id;  
    this.title  = title;  
    this.caption= caption;  
    this.message= message;
    this.url = url;
    this.target = target;  
    this.action = action;  
    this.width  = width?width:200;  
    this.height = height?height:120;  
    this.timeout= 150;  
    this.speed  = 20; 
    this.step   = 1; 
    this.right  = screen.width -1;  
    this.bottom = screen.height; 
    this.left   = this.right - this.width; 
    this.top    = this.bottom - this.height; 
    this.timer  = 0; 
    this.pause  = false;
    this.close  = false;
    this.autoHide = true;
}  
  
/** 
*隐藏消息方法  
*/  
CLASS_MSN_MESSAGE.prototype.hide = function(){  

    if(this.onunload()){  

        var offset  = this.height>this.bottom-this.top?this.height:this.bottom-this.top; 
        var me  = this;  

        if(this.timer>0){   
            window.clearInterval(me.timer);  
        }  

        var fun = function(){  
            if(me.pause==false||me.close){
                var x  = me.left; 
                var y  = 0; 
                var width = me.width; 
                var height = 0; 
                if(me.offset>0){ 
                    height = me.offset; 
                } 
     
                y  = me.bottom - height; 
     
                if(y>=me.bottom){ 
                    window.clearInterval(me.timer);  
                    me.Pop.hide();  
                } else { 
                    me.offset = me.offset - me.step;  
                } 
                me.Pop.show(x,y,width,height);    
            }             
        }