docs(grid): add example for batch edit validation

Author: Marin Bratanov

controls/grid/data-editing/edit-mode/batch-editing/validation.md

@@ -10,7 +10,55 @@ position: 5
 
 # Validation
 
-Batch editing functionality supports validation by either using the **ColumnValidationSettings** or declaring a **GridTemplateColumn** and placing a validator in the template. Note that saving the changes or	opening other cells \ rows for edit will be prevented when there is a validator that is not valid.
+Batch editing functionality supports validation by either using the **ColumnValidationSettings** or declaring a **GridTemplateColumn** and placing a validator in the **EditItemTemplate** or **InsertItemTemplate**. 
+
+>note Saving the changes or opening other cells or rows for edit will be prevented when there is a validator that is not valid.
+
+>caption Examples of a built-in required field validator and a custom validator
+
+````ASP.NET
+<telerik:RadGrid RenderMode="Lightweight" ID="RadGrid1" GridLines="None" runat="server" AllowAutomaticDeletes="True"
+				 AllowAutomaticInserts="True" PageSize="10"  AllowAutomaticUpdates="True" AllowPaging="True"
+				 AutoGenerateColumns="False"  DataSourceID="SqlDataSource1">
+	<MasterTableView CommandItemDisplay="TopAndBottom" DataKeyNames="ProductID"
+					 DataSourceID="SqlDataSource1" HorizontalAlign="NotSet" EditMode="Batch" AutoGenerateColumns="False">
+		<BatchEditingSettings EditType="Cell" />
+		<SortExpressions>
+			<telerik:GridSortExpression FieldName="ProductID" SortOrder="Descending" />
+		</SortExpressions>
+		<Columns>
+			<telerik:GridBoundColumn DataField="ProductName" HeaderStyle-Width="210px" HeaderText="ProductName" SortExpression="ProductName"
+									 UniqueName="ProductName">
+				<ColumnValidationSettings EnableRequiredFieldValidation="true">
+					<RequiredFieldValidator ForeColor="Red" Text="*This field is required" Display="Dynamic">
+					</RequiredFieldValidator>
+				</ColumnValidationSettings>
+			</telerik:GridBoundColumn>
+			<telerik:GridTemplateColumn HeaderText="Category" DefaultInsertValue="Beverages" HeaderStyle-Width="150px" UniqueName="CategoryID" DataField="CategoryID">
+				<ItemTemplate>
+				<%# Eval("CategoryName") %>
+				</ItemTemplate>
+				<EditItemTemplate>
+					<asp:TextBox ID="Textbox1" runat="server" />
+					<asp:CustomValidator runat="server" ID="myValidator" EnableClientScript="true" ClientValidationFunction="myValidation" ControlToValidate="Textbox1" ErrorMessage="Enter more than three characters"></asp:CustomValidator>
+				</EditItemTemplate>
+			</telerik:GridTemplateColumn>
+		</Columns>
+	</MasterTableView>
+	<ClientSettings AllowKeyboardNavigation="true">
+	</ClientSettings>
+</telerik:RadGrid>
+<script>
+	function myValidation(sender, args) {
+		var currValue = args.Value;
+		if (currValue.length < 3) {
+			args.IsValid = false;
+		}
+	}
+</script>
+````
+
+