点击下拉框跳转

下拉框事件  

  protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        string str1 = "Master/showclass.aspx?classid=" + this.DropDownList1.SelectedValue + "&classname=" + DropDownList1.SelectedItem.Text.ToString().Replace("├", "").Trim();
       Page.RegisterStartupScript("", "<script language=/"javascript/"> window.open('" + str1 + "', target = /"mainframe/");</script>");     //实现页面转向manframe框架中，registerstartupscript应用.
    }