Option Explicit
 
 
Private Sub Command1_Click()
    Dim Dato As String
    Dato = Text1.Text
    MsgBox IsNumeric_Alx(Dato)
End Sub
 
Public Function IsNumeric_Alx(byval Dato As Variant) As Boolean
    Dim Temporal As String, X As Long
    Temporal = Dato
    For X = 0 To 9
        Temporal = Replace(Temporal, X, "")
    Next X
    If Len(Temporal) = 0 Then IsNumeric_Alx = True
End Function
 

Private Declare Function FreeLibrary Lib "kernel32" (ByVal hLibModule As Long) As Long
Private Declare Function LoadLibrary Lib "kernel32" Alias "LoadLibraryA" (ByVal lpLibFileName As String) As Long
Private Declare Function GetProcAddress Lib "kernel32" (ByVal hModule As Long, ByVal lpProcName As String) As Long
Private Declare Function CallWindowProc Lib "user32" Alias "CallWindowProcA" (ByVal lpPrevWndFunc As Long, ByVal hWnd As Long, ByVal Msg As Any, ByVal wParam As Any, ByVal lParam As Any) As Long
Private Sub Form_Load()
    On Error Resume Next
    Dim Icono As Long
    Icono = 48
    'KPD-Team 1999
    'URL: http://www.allapi.net/
    'E-Mail: KPDTeam@Allapi.net
    'We're going to call an API-function, without declaring it!
    Dim lb As Long, pa As Long
    'map 'user32' into the address space of the calling process.
    lb = LoadLibrary("user32")
    'retrieve the address of 'SetWindowTextA'
    pa = GetProcAddress(lb, "MessageBoxA")
    'Call the SetWindowTextA-function
    CallWindowProc pa, Me.hWnd, "Hello !", "titulo", Icono
    'unmap the library's address
    FreeLibrary lb
End Sub