[SalesForce] Need some help please with pagination testing

I have 69% coverage on my controller, everything is covered accept the pagination. I need some guidance as I'm pretty new to Apex this is my second controller I've ever written. I will include the code that is related to want isn't getting covered. If someone could help me understand how to get the Next and prev page related code covered in a test class I would greatly appreciate it.

Thanks, crmprogdev, for taking time to assist me. My apologies for failing to submit a good question. I have a VF page designed to be a simplified case submission form that I will use in my communities site. It's along the lines of what is included with the Kokua template from a functionality standpoint; in that as the subject is filled it returns a listing of related possible solution articles. This functionality seem to be working but I'm having issues figuring out how to get test coverage for the related articles listing. also, I don't know if I should actually add articles as a part of my test class or not.

Like I mentioned I'm new to this and I apologize if my questions don't seem very informed. I've gone through the Salesforce Knowledge Developer Guide which was instrumental in getting the article listing on my case submission page. I've also gone through the Online Dev 401 course. I've searched the internet and found things that seem related but I think I'm missing some key concept to pull all the information together. Below is my controller and test class.

Controller:

public with sharing class submitcasecd1controller {

  private Static Final Integer PAGE_NUMBER = 10;

  public Case c { get; set; }

  public String acctNum { get; set; }

  public submitcasecd1controller() {
  String qryString = 'SELECT Id, title, UrlName, 
    LastPublishedDate,LastModifiedById FROM KnowledgeArticleVersion 
       WHERE (PublishStatus = \'online\' and Language = \'en_US\')';
      List<KnowledgeArticleVersion> articleList= 
        Database.query(qryString);
      maxSize = articleList.size() ;

      c = new Case();
      c.Status = 'New';
      c.Priority = 'Medium';
      c.Origin = 'Web';

  }

  Integer currentPage = 1;
  Integer maxSize = 1;

  public boolean getPrevRequired() {
    return currentPage > 1;
  }

  public boolean getNextRequired() {
    return currentPage * PAGE_NUMBER < maxSize;
  }

  public Decimal getCurrentPageNumber() {
    return this.currentPage;
  }

  public PageReference next() {
    if(maxSize > this.currentPage * PAGE_NUMBER) {
      this.currentPage = this.currentPage + 1;
    }
    return null;
  }

  public PageReference previous() {
    if(this.currentPage > 1)
        this.currentPage = this.currentPage - 1;
    return null;
  }

public PageReference submitCase() {
    List<Account> accts = [SELECT Id FROM Account WHERE AccountNumber = :acctNum];
    if (accts.size() != 1) {
        ApexPages.Message msg = new ApexPages.Message(ApexPages.Severity.FATAL, 'Invalid account number');
        ApexPages.addMessage(msg);
        return null;
    } else {
        try {
            c.AccountId = accts.get(0).Id;

            // now look for an associated contact with the same email
            Contact cnt = [SELECT Id FROM Contact WHERE AccountId = :c.AccountId AND Email = :c.SuppliedEmail LIMIT 1];
            if (cnt != null)
                c.ContactId = cnt.Id;

            // Specify DML options to ensure the assignment rules are executed
            Database.DMLOptions dmlOpts = new Database.DMLOptions();
            dmlOpts.assignmentRuleHeader.useDefaultRule = true;
            c.setOptions(dmlOpts);

            // Insert the case
            INSERT c;
            return new PageReference('/apex/success');
        } 
          catch (Exception e) {
            ApexPages.addMessages(e);
            return null;
        }
      }
   }    
}

Test Class:

@isTest

public class submitcasecd1contollerTest{

  Public static testMethod void submitcasecd1contollerTest() {

  System.debug('Inserting Account');

        Account tstacct       = new Account();
        tstacct.Name          = 'Acme Test Account';
        tstacct.AccountNumber = '0123456';
        insert tstacct;

  System.debug('Checking for successful Account insert.');
        Account[] ca = [SELECT Id, AccountNumber FROM Account WHERE AccountNumber = '0123456'];


  System.debug('Inserting Contact');

        Contact tstcnt        = new Contact();
        tstcnt.FirstName      = 'Fred';
        tstcnt.LastName       = 'Jones';
        tstcnt.Email          = 'fjones@gmail.com';
        List<Account> accts1 = [SELECT Id FROM Account WHERE AccountNumber = '0123456'];
        tstcnt.AccountId      = accts1.get(0).Id;
        insert tstcnt;     

  System.debug('Checking for successful Account insert.');
        Contact[] cont = [SELECT Id, AccountID FROM Contact WHERE Email = 'fjones@gmail.com'];


    PageReference pageRef = page.submitCasecd1;
    Test.setCurrentPage(pageRef);

  System.debug('Positive Results Test');    
    submitcasecd1controller controller = new submitcasecd1controller();

        controller.c.Status              = 'New';
        controller.c.Priority            = 'Medium';
        controller.c.Origin              = 'Web'; 
        controller.c.SuppliedName        = 'Fred Jones';
        controller.c.SuppliedEmail       = 'fjones@gmail.com';
        controller.c.Subject             = 'Test Case';
        controller.c.Description         = 'This is the description.';  
        controller.acctnum               = '0123456';

        controller.submitCase();

  System.debug('Test the Positive Results');
  case newrec = [SELECT Id FROM Case WHERE Subject = 'Test Case'];
  system.assertNotEquals(null, newrec);

  System.debug('Negative Results Test');       
    submitcasecd1controller controllerneg = new submitcasecd1controller();

        controllerneg.c.Status              = 'New';
        controllerneg.c.Priority            = 'Medium';
        controllerneg.c.Origin              = 'Web'; 
        controllerneg.c.SuppliedName        = 'Fred Jones';
        controllerneg.c.SuppliedEmail       = 'fjones@gmail.com';
        controllerneg.c.Subject             = 'Test Case';
        controllerneg.c.Description         = 'This is the description.';  
        controllerneg.acctnum               = '0123445'; //This acct Number doesn't exist triggers negative path.

         controllerneg.submitCase();

  System.debug('Negative Results Test, Triggers the catch');    
    submitcasecd1controller controllercatch = new submitcasecd1controller();

        controllercatch.c.Status              = 'New';
        controllercatch.c.Priority            = 'Medium';
        controllercatch.c.Origin              = 'Web'; 
        controllercatch.c.SuppliedName        = 'Fred Jones';
        controllercatch.c.SuppliedEmail       = 'fbills@gmail.com';//This incorrect email triggers the catch
        controllercatch.c.Subject             = 'Test Case';
        controllercatch.c.Description         = 'This is the description.';  
        controllercatch.acctnum               = '0123456'; 

        controllercatch.submitCase();
    }
}