Thanks you for your reply.. but
I did do that and this takes away the Date picker (small calender) next to the parameter input textbox and converts it to a drop down list of the available values.
Here are some details:
Parameter - @Date
Data Type - Date/Time
now if I dont have any Available values set it shows me the Date Picker (calender)
but if I provide the needed dates in a query form (select dates from datetable) it becomes a dropdown list of all the dates and removes the Date Picker.
Any other suggestions