def xml_entry(phase, rate):
    """
    creates the xml required for tsung (goes between the load tags)
    requires phase and rate parameters
    """
    entry = """  <arrivalphase phase="{PHASE}" duration="10" unit="minute">
    <users interarrival="{RATE}" unit="second"></users>
  </arrivalphase>"""
    line = entry.format(PHASE=phase, RATE=rate)
    return line