Vb.net code for Login page for a particular usertype

Following code is used to check whether entered login details matches and exists in the database and also it is checked whether user type is as specified.
Check code comments for more details.

Code Snippet:

Partial Class ContractorLogon
    Inherits System.Web.UI.Page

'Login button click event is below.
    Protected Sub LinkButton1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles LinkButton1.Click
        Dim sc As New SqlConnection
        Dim scmd As New SqlCommand
        Dim scmd1 As New SqlCommand
        Dim dap As New SqlDataAdapter
        Dim ds As New DataSet
        Dim user As String
        Dim currentCount As Integer = hitCounts(False)
        sc.ConnectionString = System.Configuration.ConfigurationManager.AppSettings("SiteSqlServer")

'following select statement is used to check whether entered user name and password exists in database and matches and also whether user belongs to the specified user type.
        scmd1.CommandText = "select * from USER_ROLES where PASSWORD ='" & (TextBox2.Text).ToLower() & "' and USERNAME='" & (TextBox1.Text).ToLower() & "' and USER_TYPE='Contractor'"
        scmd1.Connection = sc
        sc.Open()
        user = scmd1.ExecuteScalar
        sc.Close()

'If query conditions are satisfied then current page will be redirected to another page called Contractorform.aspx   
        If Not user Is Nothing Then
            Response.Redirect("ContractorForm.aspx")
            
'If query condition is not satisfied and number of wrong attempts is less than
3 then error message Invalid user name or password will be 
displayed.
        ElseIf user Is Nothing AndAlso currentCount <= 3 Then
            Response.Write("<script >alert('Invalid username or password')</script>")
            
            currentCount = hitCounts(True)
'If wrong attempts are greater than or equal to 3 then current page will be 
redirected to an another error page. 
            If currentCount >= 3 Then Response.Redirect("Tenanterrorpage.aspx")
        End If
    End Sub

'Following function is used to count the number of wrong attempts used to login
    Protected Shared Function hitCounts(ByVal blnCntToBeIncr As Boolean) As Integer
        Static i As Integer = 0
        If blnCntToBeIncr Then i += 1
        Return i
    End Function
End Class