I have the code below using swi Prolog and I made a interface using jframe in netbeans. 
 In this jframe I have textbox for answer and another textbox for grade.i want take answer from textbox and pass to start predicate in prolog to process answer. Can anyone tell me how I can do that? The only thing that I know is how to call predicate. 
 start(Answer,Total_grade):- 
 Question1  = "Define computer?", 
 Word_list1 = ["software","operatingsystem"], 
 Word_list2 = ["hardware","tools"], 
Msg = "Write your answers ", 
 write(Question1),nl, 
 write(Msg),nl,nl, 
 read(Answer), 
 string_lower(Answer,Low_answer), 
 split_string(Low_answer," ,.()-_"," ,.()-_", Answer_in_list), 
 find(Answer_in_list,Word_list1,Grade1), 
 find(Answer_in_list,Word_list2,Grade2), 
 Total_grade is Grade1 + Grade2, 
 nl,write("Your grade is : "), write(Total_grade),nl.