nHibernate , Linq Operand Exception

I m getting the error 'Operator '=' incompatible with operand types 'Boolean' and 'String'' when i m trying to filtering the data 开发者_StackOverflow社区in the grid with datetime column. i m using jqgrid and fluent nhibernate.

                return session.Query<User>().Where(filterExpression).Count();

on the above code i m getting the exception for search according to date time and for bool tpye also.

Does anyone knows what is the issue ?

Thanks

Can you tell us more about filterExpression? What you have so far looks correct, but expression trees are easy to get wrong.