can anyone tell me how to convert this code to vb.net it's vb6.0 code and gives error in vb.net

Dim a As Integer
Dim b As Boolean
Do While Not b And a < cmbcust.ListCount
If UCase(Left(cmbcust.List(a), Len(txtname.Text))) = UCase(txtname.Text) Then
    cmbcust.ListIndex = a
    b = True
End If
a = a + 1
Loop

please help me

Use Visual Basic Upgrade Wizard (Open the VB 6.0 project with Visual studio 2003/2005/2008).