下面这段代码有语法错误，请高手指点怎样修改，谢谢

long ll_rows_student
long ll_rows
string ls_student_id

ls_student_id = trim(sle_1.text)
DataStore lds_student
lds_student = CREATE DataStore
lds_student.DataObject = 'd_student'
lds_student.SetTransObject(SQLCA)
lds_student.SetFilter("student_id = '"+ ls_student_id + "'")
lds_student.filter()
ll_rows_student = lds_student.Retrieve()
if ll_rows_student > 0 then
    sle_2.text = lds_student.Object.student_name[ll_rows_student]
else
    MessageBox('提示','没有该学号信息,请重新输入学号!')
sle_1.SetFocus()
return
dw_1.SetFilter("score_student_id = '"+ ls_student_id +"'")
dw_1.Filter()
ll_rows = dw_1.Retrieve()
if ll_rows = 0 then
    MessageBox('提示','该学生还没有选课信息,请选课!')
    cb_1.SetFocus()
end if