title: Java code editing
body: <p>Help, I cannot get my program to run successfully. It gives me an error with two inputs for midterm mark and final mark. I cannot get it to run fully with the appropriate end pop up. I've tried to write a program that accepts marks from the user and displays the appropriate letter grade for unknown number of students. My code is as follows.</p>
  
  <pre><code>        import javax.swing.*;
      public class StudentGrades_Hann{
          public static void main (String[] args) {
              String input ;
              input= JOptionPane.showInputDialog(" Enter Name, \n ID Number,\n Homework Mark, \n Assignment Mark, \n Midterm Mark, \n and Final Mark \n All Entrys Must Be Separated By Commas");
  
              int com;
              com= input.indexOf(",");
  
              String name ;
              name = input.substring(0,com);
  
              int com2;
      com2= input.indexOf(",", com+1);
  
      String idnumber ;
      idnumber = input.substring(com+1, com2);
  
      int com3;
      com3= input.indexOf(",", com2+1);
  
      String homeworkmark ; 
      homeworkmark = input.substring(com2+1, com3);
  
      int com4;
      com4= input.indexOf(",", com3+1);
  
          String assignmentmark ; 
          assignmentmark = input.substring(com3+1, com4);
  
          int com5;
          com5= input.indexOf(",", com4+1);
  
          String midtermmark ; 
          midtermmark = input.substring(com4+1, com5);
  
          int com6;
          com6= input.indexOf(",", com5+1);
  
          String finalmark ; 
          finalmark = input.substring(com4+1);
  
          double as ;
          as = Double.parseDouble (assignmentmark.trim());
  
          double hw ;
          hw = Double.parseDouble (homeworkmark.trim());
  
          double mm ;
          mm = Double.parseDouble (midtermmark.trim());
  
  
  
          double fm ;
          fm = Double.parseDouble (finalmark.trim());
  
          String grade ; 
  
          double totalmark ; 
          totalmark= 0.1*hw+0.1*as+0.3*mm+0.5*fm ;
  
          double mnf ;
          mnf= 0.5*fm+0.3*mm ;
  
          if(totalmark &lt; 50 || mnf &lt; 50) {
              JOptionPane.showMessageDialog(null,name + idnumber + "Fail") ;
          }
          else if (totalmark &lt; 85) {
              JOptionPane.showMessageDialog(null, name + idnumber + "A") ;
          }
  
          else if (totalmark &lt; 75) {
              JOptionPane.showMessageDialog(null,name + idnumber + "B") ;
          }
  
          else if (totalmark &lt;65) {
              JOptionPane.showMessageDialog(null, name + idnumber + "C");
          }
  
          else if (totalmark &lt;=50) {
              JOptionPane.showMessageDialog(null,name + idnumber + "D") ;
          }
  
          else {
              JOptionPane.showMessageDialog(null, "Invalid Entry") ;
          }
  
      }
  
      }   
  </code></pre>