Hi Pete,
Thank you for your interest in Syncfusion Products.
We are sorry that since the link is broken, you werent able to download the sample that you mentioned. You can find the sample that you requested from the link blow.
http://help.syncfusion.com/samples/Tools.Web/6.4.0.15/78452-MultiColumnDropDownCombo/main.htmIf your intention is to dynamically populate theMultiColumnDropdown during a AJAX refresh, then you can use the DataSource property to specify the data source and then data bind using the DataBind() . The DataSource can be any object that implements the System.Collections.IEnumerable interface. You can find more details on databinding the Multicolumn Dropdown from the link below.
http://help.syncfusion.com/ug_82/ASP.NETUI_Tools/DataBinding4.htmlYou can also refer our online sample for MultiColumnDropdown in the link below
http://samples.syncfusion.com/ASPNET/8.2.0.18/Web/Tools.Web/samples/3.5/EditorsPackage/MultiColumnDropDownCombo/MultiColumnCoreFeature/cs/CoreFeature.aspx?args=0Thank you for your interest in Syncfusion Proucts.
Regards,
Lakxman Kumar C