Millisecond Forums

Is there a method by which I can move an object slowly across the screen within a trial.  I attempted to use an shape element with the position tied to a counter and repeat the call for the element within the stimulusframes argument in the trial.  However, it seems to stay where it is.
Thanks,

<block test>
/trials = [1-5= testtrial]
</block>

<trial testtrial>
/ stimulusframes = [1-1000=sequence(erase,blocky)]
/ validresponse = (" ")
/ responsetime = 0
</trial>



<shape blocky>
/ shape = rectangle
/ size = (50,20)
/ color = (0,0,0)
/ position = (expressions.xplus, expressions.yplus)
</shape>

<expressions>
/ xplus = 100-1*round(counter.county/50)
/yplus = 50
</expressions>

<counter county>
/ selectionrate = always
/ items = (1-1000)
/ select = sequence
</counter>

<shape erase>
/ shape = rectangle
/ size = (100%,100%)
/ color = (255,255,255)
/ position = (expressions.xplus, expressions.yplus)
</shape>