Why i get this Errro Exception : 503,System.Threading.ThreadAbortException: Thread was being aborted.

this is the error exception that i get when running on my page :

503,System.Threading.ThreadAbortException: Thread was being aborted.
   at System.Threading.WaitHandle.WaitOneNative(IntPtr waitHandle, UInt32 millisecondsTimeout, Boolean exitContext)
   at System.Threading.WaitHandle.WaitOne(Int32 millisecondsTimeout, Boolean exitContext)
   at System.Net.HttpWebRequest.GetResponse()
   at WEB.connect.bcastMESSMS(String user, String pass, String type, String phoneno, String from, String msg, String servid, String gid)

 any idea why this occur?
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