'...&BLAST_PROGRAM=blastx&...' sets this
to blastx.
..
Note: This parameter is optional. If specified, use blastn,
MegaBlast, and discoMegablast with 'PROGRAM=blastn';
blastp, psiBlast, and phiBlast with 'PROGRAM=blastp';
blastx with 'PROGRAM=blastx'; tblastn
with 'PROGRAM=tblastn'; and tblastx
with 'PROGRAM=tblastx'.