function Queryusno, target, dis,magrange = magrange, HOURS = hours;+; NAME: ;   QUERYUSNO;; PURPOSE: ;   Query the USNO-A2.0 Catalog at the ESO/ST-ECF Archive by position; ; EXPLANATION:;   Uses the IDL SOCKET command to query the USNO-A2.0 database over the Web.    ;   Requires IDL V5.4 or later.; ;   With the introduction of QUERYVIZIER this routine became mostly obsolete;   as the newer USNO-B1 catalog can be accessed from QUERYVIZIER.;;   USNO-A2.0 contains entries for over a half billion stars (526,230,881, to ;   be exact!) which were detected in the digitized images of three photographic;   sky surveys. For the entire northern sky and the southern sky down to ;   declinations of -30