if (Request.Form["__EVENTTARGET"]!=null && Request.Form["__EVENTTARGET"].ToString()==this.ListBox1.UniqueID+"_1111")
{
Response.Write("Double Click");
}
if (!this.Page.IsPostBack)
{

this.ListBox1.Items.Add("BB");
ListItem oItem = new ListItem("没有其他","1");
this.ListBox1.Attributes.Add("ondblclick","__doPostBack('"+this.ListBox1.UniqueID+ "_1111',this.selectedIndex);");

this.ListBox1.Items.Add(oItem);
}