Javascript for Date prompt

[tupac_rd]

Hi Gurus,

I have 2 date prompts Start Date and End Date, in a report...

I need to add default values to the date prompts, so that the start date is always the Wednesday of prior week and End Date is Tuesday (6 days after Start Date)...

so for eg. if the report is run Tuesday (April 5th 2011) or any day in the week starting March 30 2011 to April 5 2011,  then
Start Date - March 23 2011
End Date - March 29 2011

and if the report is run Wednesday (April 6th 2011) or any day in the week starting April 6 2011 to April 12 2011,  then
Start Date - March 30 2011
End Date - April 5 2011

Is there an easier way of doing it either with or without javascript etc.,

thanks
dd