date as parameter in crystal.....

My apps uses vb.net 2002 ,sqlserver 2000 and crystal 9
My report is based on parameter IDNumber and now I simply want to add date (<= date1) as a second parameter.I created a date1 (of date datatype) parameter field but when trying to assigned it to a database field using select expert ,sometimes i dont get the {?date1} thing or it just hangs forever..I am confused on whats happening....am i on right track or any other way around??I have a feeling that date might be treated differently????dunno....please help am stuck!!!
appreciating........

Try not to use the date format , just use varchar(10) and put the format yyyy/mm/dd so it will work fine with crystal report as well as sql server. if still find any problem then let me know.