Run-time Error 1004 with Data Validation

[RagonichaFulva]

Hello,

I am trying to use data validation in order to avoid that user write a value higher than 100 nor lesser than 0 in certain cells.

I previously give format to the cells with the following code:

Worksheets("Sheet1").Range(Cells(12, 6), Cells(lastrow, 56)).NumberFormat = " #,##0.0%_ ; -#,##0.0%_ ; """"??_ ;_-@_ "

Let's say that "lastrow" is 50.

Afterwards, I call the following function:

Sub aavalidation(lastrow as integer)

Worksheets("Sheet1").Range(Cells(12,6),Cells(lastrow, 56)).Select

        With Selection.Validation
            .Delete
            .Add Type:=xlValidateDecimal, AlertStyle:=xlValidAlertInformation, _
            Operator:=xlBetween, Formula1:="0", Formula2:="100"
            .IgnoreBlank = True
            .InCellDropdown = True
            .InputTitle = ""
            .ErrorTitle = "Invalid HC value"
            .InputMessage = ""
            .ErrorMessage = "The HC data you entered isn't a valid value."
            .ShowInput = True
            .ShowError = True
        End With

End Sub

When this code is executed I receive the 1004 Run-time error (Application-defined or Object Defined Error) and the debugging says that the problem is in:

.Add Type:=xlValidateDecimal, AlertStyle:=xlValidAlertInformation, _
            Operator:=xlBetween, Formula1:="0", Formula2:="100"

I would much appreciate your assistance in this issue.