#does nothing
$phidget->Invoke('DisplayString', (1,"hello"));
$phidget->Invoke('DisplayString', (2,"goodbye"));

#again, does nothing
$phidget->{"DisplayString"} = (1,"hello");
$phidget->{"DisplayString"} = (2,"goodbye");

#still does nothing
$phidget->DisplayString(1, "hello");
$phidget->DisplayString(2, "goodbye");

#This still does nothing
$phidget->{DisplayString}[0] = "hello";