Skip to after timing out

I want to skip to a different item (beyond the next one on the .que item list) if the user doesn't respond within a specified duration on a scale response item. If I create a responses.xls file and put in the value "99" and the named item in the skipto column, it ALWAYS goes to the skipto item, even if the user makes a respons within the duration allowed. How can get MediaLab to skip only when the user does not respond within the allotted time?

if you don't need the responses.xls file for anything else, you could avoid it here altogether. for each item add a duration parameter so that it times out after say 5 seconds (or whatever). Have the very next item be a simple instruction screen with no text and a duration of (d1). Give IT the skip value you want them to go to if they took too long on the previous question. Now for all the valid responses, assign skipto values that pass over that follow-up instruction item. Do you see what I'm getting at?

Thanks! Yours is a simpler solution than the one I came up with using the "responses.xls" file.
But others who might be interested in using the "responses.xls" file to create skips when the duration has timed out should be aware that MediaLab doesn't use the value "99" (missing) to indicate skips in the responses.xls file, even though this is written to the data files; instead, it writes a blank to the "values" column, so the skip condition has to be, e.g., "IF(b2="", "ontimeout", "otherwise").