selection formula error

[mis1411]

dear all
i have table students ( student_no , student _ name _student_location_Register_date, Student_country, Student_nationality )

i uam using vb6 and crystal report 7


i make the report with 4 groups
group 1= nationality
group 2= country
group 3=Locatioin
group 4=Student Number

and i call the report from the vb6 every thing is ok
no problems there

now if i make selection formula for any field it give me error

?err.Description
Error in formula <Record_Selection>.
'
'
The remaining text does not appear to be part of the formula.

this error drive me crazy always in grouping report

if i remove the selection formula
the report run without any problems



any idea
thanx

[jggtz]

Please, post the code used to set the selection formula and the text of the selection formula