Add 3 articles about RadSpreadsheet

Author: nenchef

_config.yml

@@ -1430,12 +1430,18 @@ navigation:
     "*spreadsheet/functionality/cellformat":
         title: "Cell Format"
         position: 3
+    "*spreadsheet/functionality/cellhyperlink":
+        title: "Cell Hyperlink"
+        position: 4
     "*spreadsheet/functionality/validation":
         title: "Validation"
-        position: 4
+        position: 5
     "*spreadsheet/functionality/formulas-and-functions":
         title: "Formulas and Functions"
-        position: 5
+        position: 6    
+    "*spreadsheet/functionality/multilinecellediting":
+        title: "Multiline Cell Editing"
+        position: 7   
     "*spreadsheet/client-side-programming/objects":
         title: "Objects"
         position: 0

controls/spreadsheet/client-side-programming/objects/spreadsheetsheet.md

@@ -102,5 +102,15 @@ function insertSheetRow() {
 | **set_frozenColumns** |int|none|Sets the amount of frozen columns displayed by the sheet.|
 | **get_frozenRows** |none|int|Gets the amount of frozen rows displayed by the sheet.|
 | **set_frozenRows** |int|none|Set the amount of frozen rows displayed by the sheet.|
+| **set_showGridLines** |bool|none|Togles the visibility state of the GrigLines in the sheet.|
 
+````JavaScript	
+
+function insertSheetRow() {
+    var spreadsheet = $find("<%= RadSpreadsheet1.ClientID %>");
+    var activeSheet = spreadsheet.get_activeSheet();
+    activeSheet.set_showGridLines(false); //hides the grid lines in the active sheet
+}
+
+````
 

controls/spreadsheet/functionality/cellhyperlink/images/spreadsheet-hyperlinkpopup.png

@@ -0,0 +1,45 @@
+---
+title: Overview
+page_title: RadSpreadsheet Cell Hyperlink Overview | UI for ASP.NET AJAX Documentation
+description: CellHyperlink Overview
+slug: spreadsheet/functionality/cellhyperlink/overview
+tags: overview
+published: True
+position: 0
+---
+
+# Cell Format Overview
+
+As from R3 2016 **RadSpreadsheet** provides the ability to define hyperlink for its cells content. 
+
+You can define a hyperlink for a given cell in two ways:
+
+1. Using the ToolbarTab(see **Figure 1**), which will prompt you with a popup, where you can set the needed url (see **Figure 2**)
+
+	>caption Figure 1 shows the ToolbarTab used to open the popup.
+	**Figure 1**: 
+	![ToolbarTab](images/spreadsheet-toolbartab.png) 
+
+	>caption Figure 2 illustrates the popup where you can set the hyperlink for the cell.
+	**Figure 2**: 
+	![Hyperlink Popup](images/spreadsheet-hyperlinkpopup.png) 
+
+	From the popup, you can also remove a hyperlink, using the **Remove link** button.
+
+2. Programatically, using the Client API of the RadSpreadsheet and the SpreadsheetRange object.
+
+	>caption The following example demonstrates how to programatically set hyperlink for a certain cell.
+	
+	````JavaScript	
+
+	function setHyperlink() {
+		var spreadsheet = $find("<%= RadSpreadsheet1.ClientID %>");
+		var activeSheet = spreadsheet.get_activeSheet();
+		var singleCellRange = activeSheet.get_range("B3")
+		singleCellRange.set_link("www.telerik.com");
+	}
+	
+	````	
+	
+## See Also
+[RadSpreadsheet Full Set of Tools Demo](http://demos.telerik.com/aspnet-ajax/spreadsheet/examples/spreadsheettoolbar/defaultcs.aspx)

controls/spreadsheet/functionality/cellhyperlink/images/spreadsheet-toolbartab.png

@@ -0,0 +1,21 @@
+---
+title: Overview
+page_title: RadSpreadsheet Multiline Cell Editing Overview | UI for ASP.NET AJAX Documentation
+description: Multiline Cell Editing Overview
+slug: spreadsheet/functionality/multilinecellediting/overview
+tags: overview
+published: True
+position: 0
+---
+
+#  Multiline Cell Editing Overview
+
+As from R3 2016 **RadSpreadsheet** provides the ability for multiline editing for its cells content. In order to go to a new line, you can use the Alt+Enter buttons combination(see **Figure 1**). 
+
+
+>caption Figure 1 demonstrates the multiline editing feature.
+**Figure 1**: 
+![MultiLineEditing](images/spreadsheet-multilineediting.png)
+
+## See Also
+[RadSpreadsheet Full Set of Tools Demo](http://demos.telerik.com/aspnet-ajax/spreadsheet/examples/spreadsheettoolbar/defaultcs.aspx)