def find_proc_date(header):
    """Search the HISTORY fields of a header looking for the FLIPS
    processing date.
    """
    import string, re
    for h in header.ascardlist():
        if h.key=="HISTORY":
            g=h.value
            if ( string.find(g,'FLIPS 1.0 -:') ):
                result=re.search('imred: FLIPS 1.0 - \S{3} (.*) - ([\s\d]\d:\d\d:\d\d)\s*$',g)
                if result:
                    date=result.group(1)
                    time=result.group(2)
                    datetime=date+" "+time
                    return datetime
    return None
Search the HISTORY fields of a header looking for the FLIPS
    processing date.