Code:
        For Each file As String In IO.Directory.GetFiles("C:\folder")
            Dim temp As String() = IO.File.ReadAllLines(file)
            If temp(0) = "<?php require_once('Connections/connCJ.php'); ?>" Then
                temp(0) = "<?php include('mobile_device_detect.php'); mobile_device_detect('http://www.campjellystone.mobi/','http://www.campjellystone.mobi/','http://www.campjellystone.mobi/','http://www.campjellystone.mobi/','http://www.campjellystone.mobi/','http://www.campjellystone.mobi/','http://www.campjellystone.mobi/',false); ?><?php require_once('Connections/connCJ.php'); ?>"
                IO.File.WriteAllLines(file, temp)
            End If
        Next