implicit conversion from data type varchar to varbinary(max)

string filename = Path.GetFileName(FileUpload1.PostedFile.FileName);

string contentType = FileUpload1.PostedFile.ContentType;

using (Stream fs = FileUpload1.PostedFile.InputStream)

{

using (BinaryReader br = new BinaryReader(fs))

{

byte[] bytes = br.ReadBytes((Int32)fs.Length);

string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;

using (SqlConnection con = new SqlConnection(constr))

{

con.Open();

string query = "UPDATE tblFiles SET Name='" + filename.ToString() + "',ContentType='" + contentType.ToString() + "',Data='" + ((object)bytes) + "' WHERE id = '" + 1 + "'"; //Getting error

using (SqlCommand cmd = new SqlCommand(query))

{

cmd.Connection = con;

cmd.ExecuteNonQuery();

con.Close();

}

}

}

}

Response.Redirect(Request.Url.AbsoluteUri);