.cs code :-

//get a reference to the grid in the combo

UltraWebGrid grid = (UltraWebGrid)cmbApplication.Controls[0];

if (grid != null)

            {

                //set some properties of the grid to act and look like a combo

                grid.Columns.FromKey("Checked").AllowUpdate = AllowUpdate.No;

                grid.Columns.FromKey("Id").Hidden = true;

            }

            //set clientside events Combo box Properties for look

            cmbApplication.DropDownLayout.RowSelectors = Infragistics.WebUI.UltraWebGrid.RowSelectors.No;

            cmbApplication.DropDownLayout.GridLines = UltraGridLines.None;

            cmbApplication.DropDownLayout.ColHeadersVisible = ShowMarginInfo.No;

            cmbApplication.Editable = false;

    }

WebDropDown Code:-

<ig:WebDropDown ID="WddcmbApplication" runat="server" MultipleSelectionType="Checkbox" EnableClosingDropDownOnSelect="false"  DisplayMode="DropDownList" EnableMultipleSelection="true" ></ig:WebDropDown>

if (grid1 != null)

            {     grid1.ClientEvents.Click = "GridCellClickHandler";

                //needed equivalent code in webdataGrid for below code

                grid1.Columns.FromKey("Checked").AllowUpdate = AllowUpdate.No;

                grid1.Columns.FromKey("Checked").CellStyle.BorderWidth = Unit.Pixel(0);

                grid1.Columns.FromKey("Id").Hidden = true;

             }

javascript code :-

document.onclick = function (evt) {

     var oCombo = ig_controls.WddcmbApplication;

     var div = oCombo.getGrid().getDivElement(); //giving error, need Equivalent line for webdropdown

    if(div.id== “Test”)

    {

            oCombo.setDropDown(false); //giving error, need Equivalent line for webdropdown

    }

}

thanks

Ravi