Protected Sub getproduct_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles getproduct.Click
        Dim x As String
        x = Session("user")
        Dim LongTimeString As String = ""
        Dim DateToString As String = ""
        Dim ShortTimeString As String = ""
        Dim LongDateString As String = ""
        Dim Daysinmonth As Integer = 0
        Dim ErrorStr As String = ""
        Dim ErrorStr1 As String = ""
        con = New OleDbConnection
        Dim cmd As OleDbCommand = New OleDbCommand
        Dim Add As String
        con.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source='C:\Documents and Settings\USER\Desktop\my\WebSite2\App_Data\EC.mdb';Persist Security Info=True"
        If con.State = Data.ConnectionState.Closed Then
            con.Open()
        End If
        Dim OrderDate = System.DateTime.Now
        LongTimeString = OrderDate.ToLongTimeString
        Daysinmonth = System.DateTime.DaysInMonth(OrderDate.Year, OrderDate.Month)
        DateToString = OrderDate.ToString
        ShortTimeString = OrderDate.ToShortTimeString
        LongDateString = OrderDate.ToLongDateString
        If (product.Text = "") Then
 
            ErrorStr = ErrorStr & " Please Enter Product number, "
        End If
        If (Quantity.Text = "") Then
 
            ErrorStr1 = ErrorStr1 & " Please Enter Product quantity, "
        End If
        Dim pri = "SELECT price FROM product WHERE ProductNO='" & product.Text & "'"
 
        cmd.Connection = con
        cmd.CommandText = pri
        Dim s As String = cmd.ExecuteScalar()
        Add = "INSERT INTO order Values ('" & 1 & "','" & Quantity.Text & "','" & pri & "','" & Daysinmonth & "','" & x & "','" & product.Text & "');"
        cmd.CommandText = Add
        Try
            cmd.ExecuteNonQuery()
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
 
 
 
 
    End Sub

While (i <= 100)
            i = (i + 1)
 
 
            Dim pri = "SELECT price FROM product WHERE ProductNO='" & product.Text & "'"
 
            cmd.Connection = con
            cmd.CommandText = pri
            Dim s As String = cmd.ExecuteScalar()
            Dim a As String
            a = ("INSERT INTO order Values ( i  And Quantity.Text  And pri And  Daysinmonth And  x And  product.Text );")
            cmd.CommandText = a
        End While

Add = "INSERT INTO order Values ('" & 1 & "','" & Quantity.Text & "','" & pri & "','" & Daysinmonth & "','" & x & "','" & product.Text & "');"

Add = "INSERT INTO order Values (1," & Quantity.Text & "," & pri & "," & Daysinmonth & "," & x & "," & product.Text & ");"

INSERT INTO tblname (column1, column2, column3.....) VALUES (value1, value2, value3.....)

Add = "INSERT INTO tblname (column1, column2, column3, ....) VALUES (?, ?, ?, ....)"
cmd.Parameters.AddWithValue( "?ColumnName", value )

Add = "INSERT INTO tblname (column1, column2, column3, ....) VALUES (?, ?, ?, ....)"
cmd.Parameters.AddWithValue( "?Column1", value1 )
cmd.Parameters.AddWithValue( "?Column2", value2 )
cmd.Parameters.AddWithValue( "?Column3", value3 )