How to wget a file when the filename isn't known?

[Provac]

I am trying to automate the download of a file using wget and calling the php script from cron, the filename always consists of filename and date, however the date changes depending on when the file is uploaded. The trouble is there is no certainty of when the file is updated, and hence the final name can never really be known until the directory is checked.An example filename is file20100818.tbzI tried using wildcards within wget but they have failed, both using * and %Thanks in advance,Greg