Telerik RadComboBox with CheckBox

Here is some useful links to put ComboBox inside RadDropDownList.
(1) Using CheckBoxes for multi-item selection - ComboBox Code Library - RadControls for ASP.NET and ASP.NET AJAX

(2) CheckBox inside a RadcomboBox - Combobox Forum - ASP.NET Classic Controls

(3) Implementing checkbox items in RadComboBox - RadControls for WinForms (Telerik Knowledge Base)

(4) Checkbox in RadComboBox - Combobox Forum - ASP.NET Classic Controls

(5) Count the Checkbox checked in a radcombobox with Javascript - Combobox Forum - ASP.NET Classic Controls

- Check all checkbox in RadCombobox

(1) Checkbox in RadComboBox - Combobox Forum - ASP.NET Classic Controls

(2) Looping through the comboBox with checkbox inside in javascript - ComboBox Forum - ASP.NET Controls

(3) Select All items in checkbox in combobox - ComboBox Forum - ASP.NET Controls

(4) Combobox with checkboxes and select all - ComboBox Code Library - RadControls for ASP.NET and ASP.NET AJAX

(5) ComboBox Checkboxes - Combobox Forum - ASP.NET Classic Controls