To hop cua mot so

**Admin** Thu Feb 10, 2011 8:21 am

Code:: Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim N, P, TH As Integer N = CInt(txtN.Text) P = CInt(txtP.Text) If N - P < 0 Then ErrorProvider1.SetError(txtN, "N phai lon hon P") Label4.Visible = True Label4.Text = ErrorProvider1.GetError(txtN) 'MsgBox("N khong be hon P", vbOKOnly + vbCritical, "Warning") txtN.Text = "" txtP.Text = "" Return Else TH = 1 For i = 1 To P TH = TH * (N - i + 1) / i Next End If MsgBox("To hop " & N & " chap " & P & " la: " & TH, vbOKOnly + vbCritical, "Ket Qua") txtN.Text = "" txtP.Text = "" End Sub