Vista - $args.count

if ($args.count -lt 4)
{
write-host "powershell.exe .\filegrp_day.ps1 <directory> <start-date >
<end-date> <powergadget template>"
break
}

======================================
i would like to script to accept only 3 or 4 parameters.

The line parameter <powergadget template> is optional. Those <directory>
<start-date > <end-date> are mandatory parameters
How shld i go about that ?