SRW.SET_PDF_ACTION is not working

The following snippet of code in format trigger does not work:

vURL := 'http://<host>:9002/reports/rwservlet?'||:p_drill_down||'&report=dtlsoc.rep'||
                      '&paramform=no&destype='||:destype||'&desformat='||:desformat||
                      '&p_appr='||:appr_apprcode||
                      '&p_bfy='||:appryear||
                      '&p_dept='||:appr_dept||
                      '&p_fund='||:appr_fund ||
                      '&p_action=xyz'||
                      '&p_sdate=0601'||substr(to_char(to_number(:appryear-1)),3,4)||
                      '&p_biids_usr='||user||
                      '&p_edate='||to_char(trunc(sysdate)-1,'mmddrr')||
                      '&server='||:p_server||'&p_server='||:p_server||'&mimetype=application/pdf';