I have just started working groovy and grails and has some confusion on Order clause with criteria.

Below is my code,

```
def order = "rollNumber"
def orderBy = "asc"

studentListCriteria = Students.createCriteria()

int max = 6
int offset = params?.offset ? Integer.valueOf(params.offset) : 0

def studentList = studentListCriteria.list(max: max, offset: offset) {
        and {
            eq("isActive", Boolean.TRUE )
        }
        order(order,orderBy)
    }

```

While executing it's throw below error.

```
groovy.lang.MissingMethodExceptionMessageNo signature of method: java.lang.String.call() is applicable for argument types: (java.lang.String, java.lang.String) values: [rollNumber, asc] Possible solutions: wait(), any(), tr(java.lang.String, java.lang.String), trim(), find(), size()   

```

Can anyone suggest what am i doing wrong here??