/// <summary>

            /// Launches the DatePicker page in a popup window,

            /// passing a JavaScript reference to the field that we want to set.

            /// </summary>

            /// <param name="strField">String. The JavaScript reference to the field that we want to set,

/// in the format: FormName.FieldName

            /// Please note that JavaScript is case-sensitive.</param>

            function calendarPicker(strField)

            {
                        var winl = (screen.width-230)/2;
                        var wint = (screen.height-210)/2;
                        window.open('Calendar.aspx?field=' + strField, 'calendarPopup', 'top='+ wint + ',left=' + winl +  ' ,width=230,height=210,resizable=no');

            }