numbers only

Question

i have two text boxes and i need them so the user can enter number from 0 to 23 and that's what i've done but if user enters some text an error apears, now what i need is the messagebox to notice the user that he needs to enter an number from the 0-23 diameter

joy.simpson · Answer

Place the following code in the TextBox Leave event: Private Sub TextBox1_Leave(ByVal sender As Object ByVal e As System.EventArgs) Handles TextBox1.Leave Dim num As Integer snum As String snum = TextBox1.Text num = Val(snum) If num = 0 And snum 0 Or num 23 Then MessageBox.Show(Enter number between 0-23 Out of range) TextBox1.Clear() TextBox1.Focus() End If End Sub You can force the textbox to accept only numbers in the KeyPress event: Private Sub TextBox1_KeyPress(ByVal sender As Object ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress If Char.IsNumber(e.KeyChar) = False Then e.Handled = True End If End Sub