Controller class Bold Text lines are not covering

public class AddPaymentController {
 public Payment__C paymentObj {get;set;}
 Public String invId {get;set;}
    public AddPaymentController(ApexPages.StandardController controller) {
       if(paymentObj == null) {
           paymentObj = new Payment__C();
           String invId = ApexPages.CurrentPage().getParameters().get('invid');
             if(invId !=null) {
     Invoice__c invObj = [Select Prospect_Client__r.ShippingPostalCode,Prospect_Client__r.ShippingState,Prospect_Client__r.Cell_Phone__c,Prospect_Client__r.Email__c,Prospect_Client__r.ShippingStreet,Prospect_Client__r.Name,Prospect_Client_City__c,Name,Id From Invoice__c i where id =:invId];
                           
                      if(invObj !=null) {
                          paymentObj.invoice_numbers__c = invObj.Name;
                          paymentObj.Invoice_Number__c = invObj.id;                        
                          paymentObj.City__c=invObj.Prospect_Client_City__c;         
                          paymentObj.State__c=invObj.Prospect_Client__r.ShippingState;
                          paymentObj.Zip__c=invObj.Prospect_Client__r.ShippingPostalCode;
                          paymentObj.Name__c=invObj.Prospect_Client__r.Name;
                          paymentObj.Street__c=invObj.Prospect_Client__r.ShippingStreet;
                          paymentObj.Phone__c=invObj.Prospect_Client__r.Cell_Phone__c;
                          paymentObj.Email_Address__c=invObj.Prospect_Client__r.Email__c;    
                         
                      }                           
             }
       }
    }       
   public Pagereference save(){
   
       if(paymentObj.Amount__c==null)
       {
       ApexPages.Message myMsg = new ApexPages.Message(ApexPages.Severity.ERROR,'please enter Amount and insert.');
            ApexPages.addMessage(myMsg);
       }                         
         upsert paymentObj;
        //  ApexPages.AddMessage(new ApexPages.Message(ApexPages.Severity.CONFIRM,'Payment Created Successfully.Thank you!'));   
          Pagereference refpyob = new Pagereference('/apex/Invoice?id='+paymentObj.Invoice_Number__c);                   
          refpyob.setRedirect(true);
          return refpyob;                                      
}       
}

test class i am getting 84 percent


@isTest

public with sharing class TestAddPaymentController{
  public static testMethod void unitTestInvoice7()
  {
 try{
 
// String strRetUrl = ApexPages.CurrentPage().getParameters().put('retURL','/apex/AddPaymentVFPage');
       User objUser =[select Id, Name ,Email from User Where UserName = 'naveen@cloudprousa.com.test'];
          
          Staff__c objStaff = new Staff__c(User__c = objUser.Id,Name='Naveen1',Last_Name__c='Alasapuri1');
          insert objStaff;
          
          Account objAcc = new Account(Name = 'Test Prospect4', OwnerId=objUser.Id, Company_Name__c='test',Sales_Consultant__c = objStaff.Id,
                         Cell_Phone__c='987', ShippingStreet='test', ShippingCity='test', ShippingState='NJ');
          insert objAcc;
            Lead_Source__c objLS = new Lead_Source__c ( Name = 'Test Lead',Sales_Consultant__c =objStaff.Id);
      insert objLS;
          
            //SalesWorksheet record insertion
            
            Salesworksheet__c objSW = new Salesworksheet__c(C_Adjustment__c = 10,Lead_Source__c=objLS.Id);
            insert objSW;
            
            //User objUser =[select Id from User Where UserName = 'naveen@cloudprousa.com.test'];
            
            //Staff__c objStaff = new Staff__c(User__c = objUser.Id);
            //insert objStaff;
            
            Invoice__c objInv = new Invoice__c(Sales_Worksheet__c = objSW.Id);
            insert objInv;
            

            
            objSW.Technician__c = objStaff.Id;
            update objSW;
        //Payment record insertion
      Payment__c objPayment= new Payment__c(Amount__c=1000);
      insert objPayment;
        
     // insert objInv;
      String strInvId = ApexPages.CurrentPage().getParameters().put('invid',objInv.id);
      
         
      
      
      ApexPages.StandardController controller = new ApexPages.StandardController(objPayment);
      AddPaymentController objCGC = new AddPaymentController(controller);
      objCGC.save();
       //ApexPages.currentPage().getParameters().put('invid',objInv.id);
       
       
      // ApexPages.Message[] pageMessages = ApexPages.getMessages();
     //      System.assertNotEquals(0, pageMessages.size());
           
          
     //  PageReference pageRef =Page.Invoice;
     // Test.setCurrentPageReference(pageRef);
     
   //   ApexPages.CurrentPage().getParameters().put('retURL','/apex/Invoice?id='+objInv.Id);
       
    
    }catch(exception e)
    {
      system.debug('Exception..'+e);
    }
  }
 
  public static testMethod void unitTestInvoice8()
  {
 try{
 
// String strRetUrl = ApexPages.CurrentPage().getParameters().put('retURL','/apex/AddPaymentVFPage');
       User objUser =[select Id, Name ,Email from User Where UserName = 'naveen@cloudprousa.com.test'];
          
          Staff__c objStaff = new Staff__c(User__c = objUser.Id,Name='Naveen1',Last_Name__c='Alasapuri1');
          insert objStaff;
          
          Account objAcc = new Account(Name = 'Test Prospect4', OwnerId=objUser.Id, Company_Name__c='test',Sales_Consultant__c = objStaff.Id,
                         Cell_Phone__c='987', ShippingStreet='test', ShippingCity='test', ShippingState='NJ');
          insert objAcc;
            Lead_Source__c objLS = new Lead_Source__c ( Name = 'Test Lead',Sales_Consultant__c =objStaff.Id);
      insert objLS;
          
            //SalesWorksheet record insertion
            
            Salesworksheet__c objSW = new Salesworksheet__c(C_Adjustment__c = 10,Lead_Source__c=objLS.Id);
            insert objSW;
            
            //User objUser =[select Id from User Where UserName = 'naveen@cloudprousa.com.test'];
            
            //Staff__c objStaff = new Staff__c(User__c = objUser.Id);
            //insert objStaff;
            
            Invoice__c objInv = new Invoice__c(Sales_Worksheet__c = objSW.Id);
            insert objInv;
            

            
            objSW.Technician__c = objStaff.Id;
            update objSW;
        //Payment record insertion
      Payment__c objPayment= new Payment__c(Amount__c=1000);
      insert objPayment;
        
     // insert objInv;
     // String strInvId = ApexPages.CurrentPage().getParameters().put('invid',objInv.id);
      
         
             

       
      
      ApexPages.StandardController controller = new ApexPages.StandardController(objPayment);
      AddPaymentController objCGC = new AddPaymentController(controller);
      objCGC.save();
      
      PageReference testPage = new pagereference('/apex/Invoice?id='+objInv.Id);
      //change the following to opp.id instead of 'opp.id'
      //   testPage.getParameters().put('invid',objInv.id);

               Test.setCurrentPage(testPage);                    
    }catch(exception e)
    {
      system.debug('Exception..'+e);
    }
  }
 
 
}