textbox与Calendar的绑定

protected void Page_Load(object sender, EventArgs e)     {         this.Calendar1.Attributes.Add("style", "display:none;border-width:1px;border-style:solid;border-collapse:collapse;z-index: 100; left: 0px;");         TextBox1.Attributes.Add("onfocus", "javascript:document.getElementById('Calendar1').style.display=''");     }     protected void Calendar1_SelectionChanged(object sender, EventArgs e)     {         TextBox1.Text = this.Calendar1.SelectedDate.ToShortDateString();         Calendar1.Attributes.Add("onblur", "javascript:document.getElementById('Calendar1').style.display='none'");     }     protected void Button1_Click(object sender, EventArgs e)     {         Console.Write(this.TextBox1.Text);