def post_string(descr):
    """Constructs a http POST description string from dataset description"""
    
    output = "dsid=ds%(dsid)s&rtype=S&rinfo=dsnum=%(dsid)s;\
startdate=%(startdate)s;enddate=%(enddate)s;parameters=%(parameters)s;\
level=%(level)s;product=%(product)s;grid_definition=%(grid_definition)s;ststep=%(ststep)s;" % descr
    return output
    #nlat=%(nlat)s;slat=%(slat)s;wlon=%(wlon)s;elon=%(elon)s