Multiple sheet formatting based on cell info

Sub test()
Dim color As Long, j As Integer, sh As String
 Dim r As String, k As Integer, ws As worksheet
 Dim cfind As Range, x
 sh = InputBox("type the name of sheet you want to conider first, e.g. sheet1")
r = InputBox("the cell you want to select, e.g. C2")
j = Worksheets.Count
Set ws = Worksheets(sh)
sh = ws.Name
ws.Activate
ActiveSheet.Range(r).Interior.ColorIndex = 3
x = Range(r).Value
For k = 1 To j
If Worksheets(k).Name = sh Then GoTo nextk
With Worksheets(k)
Set cfind = .Cells.Find(what:=x, lookat:=xlValue)
If cfind Is Nothing Then GoTo nextk
cfind.Interior.ColorIndex = 3
End With
nextk:
Next k

End Sub

Sub undo()
Dim j As Integer, k As Integer
j = Worksheets.Count
For k = 1 To j
Worksheets(k).Cells.Interior.ColorIndex = xlNone
Next k
End Sub