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   QUERY()                  User query condition builder
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     Usage      QUERY_COND = QUERY(<# FIELDS>,<FIELD ARRAY>,
                                                <FIELD DESCR ARRAY>)

     Params        <#fields>         -number of fields in array
                   <fieldname array> -array of fields to use
                   <fielddesc array> -array of field descriptions
                   (all optional)
     Example
                   ...
                   USE CUSTOMER
                   private flds[3],fdes[3]
                   flds[1] = "fname"
                   flds[2] = "lname"
                   flds[3] = "mi"
                   fdes[1] = "First Name"
                   fdes[2] = "Last Name"
                   fdes[3] = "Middle Initial"
                   qcond = "lastname > 'CCCC' "
                   filt = query(3,flds,fdes)
                   set filter to &filt
                   ...
                   or
                   ...
                   USE CUSTOMER
                   looker = query()
                   locate for &looker
                   ...

     Returns    QUERY CONDITION STRING

     ALSO       MAKES VARIABLE 'QUERY_EXP' PUBLIC. This contains
                the current query expression, which is retained
                between calls of query, and is looked for by some of
                the other SuperFunctions.

     Note       Query could bomb out, by the user attempting to restore
                a query condition from the disk that does not match
                the dbf- although the dbf name is stored to disk and
                along with the Query, and only stored queries with the
                matching dbf name are allowed to be restored.


     INTERNAL FUNCTIONS:
       Q_ALT_BLD()       Q_CTL_()          Q_OP_D()          Q_DUMMY()
       Q_ALT_GET()       Q_CURR_GET()      Q_FLD_GET()       Q_OPS_GET()
       QU_ANDOR()        Q_SAY_CON