Validate a textbox

Hello,

I'm trying to validate a TexBox as a %, from 1 to 100. I suppose it's very simple but somehow i can't . My code is:

PHP Code: 

Private Sub CommandButton1_Click()
    Dim Procent As Integer
    Procent = TextBox1.Value
    
    If Procent = "" Then
    MsgBox "Please type in a number between 1 and 100 %", vbOKOnly + vbInformation, "Enter Password"
    ElseIf Procent > 100 Then
    MsgBox "Please type in a number between 1 and 100 %", vbOKOnly + vbInformation, "Enter Password"
    Else
    Label5.Caption = TextBox1.Value
    Label7.Visible = True
    TextBox1.Value = ""
    End If
End Sub 


Here it gives me an error on Procent = TextBox1.Value. How can I validate only numbers between 1 and 100 to be in the TextBox?