Sham,

Assuming a userform, this will do as you ask

Private Sub TextBox1_BeforeUpdate(ByVal Cancel As MSForms.ReturnBoolean)
With Me.TextBox1
If Not IsNumeric(.Text) Then
.SelStart = 0
.SelLength = Len(.Text)
.SetFocus
Cancel = True
MsgBox "Invalid data"
End If
End With
End Sub

An alternative is to trap the input, and only allow numerics

Private Sub TextBox1_KeyPress(ByVal KeyAscii As MSForms.ReturnInteger)
If KeyAscii < 48 Or KeyAscii 57 Then
Application.EnableEvents = False
KeyAscii = 0
Application.EnableEvents = True
End If
End Sub


--

HTH

Bob Phillips
... looking out across Poole Harbour to the Purbecks
(remove nothere from the email address if mailing direct)

"Shamsul" wrote in message
...
Hi

How can you restrict users from only entering numbers in a
textbox; and if text was entered a error message will be
displayed.

Thanks

Sham