Shoutbox

Hello, i have a question on this script display pic changer. I wanted to know whether we can set the timing "Every something seconds" to mili seconds, for instance, in this case, i would like to put 0.5 seconds.
I tried to put any timing that is less than 1 second, it doesn't change the display picture but instead the timing was changed to 1800 seconds straight away.
The reason why i would like to put it as 0.5 seconds is that i would like to have an animated picture in my dp.

Hope help given.