title: Conversion from type 'DBNull' to type 'String' is not valid
body: <p>i am receiving this problem</p>
  
  <blockquote>
    <p>Conversion from type 'DBNull' to type 'String' is not valid. </p>
    
    <p>Line 501:                        hfSupEmail.Value =
    dt.Rows(0)("SupEmail")</p>
  </blockquote>
  
  <p>i am very new to this, i am not really sure what is the exact problem
  could someone guide me?</p>
  
  <p>Many thanks</p>