Below is a code snippit I found in one of your forums. It was working fine until I turned on filtering. Now "id" in
gridHeader.childNodes[i].id is null so it fails on ".indexOf". function BulkOperationRadGrid_GridCreated(sender, eventArgs) { var masterTable = sender.get_masterTableView(); //check whether all items on the active page are selected if (masterTable.get_selectedItems().length == masterTable.get_pageSize()) { /*find the checkbox in the header of the GridClientSelectColumn and set checked state for it - will work with AllowMultiRowSelection = true only!*/ var gridHeader = masterTable.get_element().getElementsByTagName("TH")[0]; for (var i = 0; i < gridHeader.childNodes.length; i++) { if (gridHeader.childNodes[i].id.indexOf("columnSelectCheckBox") > -1) { gridHeader.childNodes[i].checked = "true"; } } }