I'm trying to get some data from a WebService using SOAP request. The SOAP body should contain an SQL query. Whenever I'm using the < character it causes the above mentioned error at SOAPReqBody.LoadXml(). How can I fix this?
HttpWebRequest request = CreateSOAPWebRequest();
XmlDocument SOAPReqBody = new XmlDocument();
SOAPReqBody.LoadXml(@"<?xml version=""1.0"" encoding=""utf-8""?>
 <soap:Envelope xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"" xmlns:xsd=""http://www.w3.org/2001/XMLSchema"" xmlns:soap=""http://schemas.xmlsoap.org/soap/envelope/"">
 <soap:Body>  
    <Query xmlns=""http://LifaOIS.DK/OISService"">
      <UID>" + uid + @"</UID>
      <PWD>" + pwd + @"</PWD>
      <SQL>" + sql + @"</SQL>
      <Meta>" + meta + @"</Meta>
     </Query>
  </soap:Body>  
</soap:Envelope>");
 
     
    