Hi,
Go to the 'developer' tab and click on 'Insert' and then click the command button icon in the ActiveX toolbox. On the worksheet hold down the left mouse button and drag to draw a button on the sheet in the appropriate place. Right click the button and view code and paste the code below into the editor. Back on the worksheet click the button and the rows will either hide or unhide depending upon the current state and the button caption will change to the correct one.
Private Sub CommandButton1_Click()
Dim x As Long, LastRow As Long
LastRow = Cells.Find(What:="*", After:=[A1], _
SearchOrder:=xlByRows, _
SearchDirection:=xlPrevious).Row
For x = 11 To LastRow Step 2
Rows(x).Hidden = Not Rows(x).Hidden
Next
If Rows(11).Hidden Then
CommandButton1.Caption = "Show Plan"
Else
CommandButton1.Caption = "Hide Plan"
End If
End Sub