给RadionButtonList控件加onclick属性

RadionButtonList _Specialclassid;

_Specialclassid = (RadioButtonList)this.FindControl("Specialclassid");

if (_Specialclassid != null)
            {
                foreach (ListItem obj in _Specialclassid.Items)
                {
                    obj.Attributes.Add("onclick", "Showdate(this)");
                   // _Specialclassid.Items[1].Attributes.Add("onclick", "Showdate('" + _Specialclassid.SelectedValue + "')");
                }
                
            }