I need a bit more help writing my first test class.  Below is the code that i've modified for our environment.  I've also included the start of my test case.   I've got my test class working now. I've pasted the updated class below.  I'm having a problem getting more than 66% code converage.  When I look at my code coverage in my trigger my test class doesn't cover the two lines below in bold.  Please advise.  

closingprojects.add(p.id);

trigger.newmap.get( (id)ar.get('Id')).pse__Is_Active__c.adderror('This is a customer Project - You cannot set project to inactive until all Milestones are closed.');

How do I test these above lines in my test class?
----

The Trigger

// Looks at active projects and checks to see if any milestones are open
// If a milestone is open and a user tries to set a project to inactive then return a message to user

trigger OpenMilestoneTrigger on pse__Proj__c (before update) {

// Creates set of all active projects
set<id> closingprojects = new set<id>();
for(pse__Proj__c p:trigger.new)

// if(p.RecordTypeId == '012Z00000000JWKIA2'&&(p.pse__Stage__c=='Completed'&&trigger.oldmap.get(p.id).pse__Stage__c!='Completed'))
// sets the RecordTypeID for the Customer record

if(p.RecordTypeId == '012Z00000000JWKIA2'&&(p.pse__Is_Active__c == false && trigger.oldmap.get(p.id).pse__Is_Active__c == true))

// Adds active projects to the closingprojects set
closingprojects.add(p.id);

// Checks to see if there are any open milestones within the closing projects set
for(AggregateResult ar:[SELECT pse__Project__c Id,COUNT(Id) FROM pse__Milestone__c
WHERE pse__Project__c IN :closingprojects AND pse__Status__c != 'Approved' GROUP BY pse__Project__c])

// If there are open milestones then add them to the newmap and send error to user
trigger.newmap.get( (id)ar.get('Id')).pse__Stage__c.adderror('This is a customer Project - You cannot set project to inactive until all Milestones are closed.');

}

----

The Test Class

@isTest
private class OpenMilestoneTriggerTestClass {

private static testMethod void validateOpenMilestoneTriggerNegative() {

//Setup the Project Record
pse__Proj__c p = new pse__Proj__c();
p.RecordTypeId = '012Z00000000JWKIA2';
p.Name='TestProject';
p.pse__Region__c = 'a0wZ0000000WMArIAO';
p.pse__Is_Active__c = true;

insert p;

//Setup the Milestone Record
pse__Milestone__c m = new pse__Milestone__c();
m.Name = 'TestMileStone';
m.pse__Project__c = p.ID; //[Select pse__Proj__c.Name from pse__Proj__c where pse__Proj__c.Name = :pse__Proj__c.id];
m.pse__Milestone_Amount__c = 0;
m.pse__Target_Date__c = Date.today();

insert m;

Test.startTest();

//Set the project status to inactive
try
{
p.pse__Is_Active__c = false;

}
Catch (System.DMLException e)
{
System.assert(e.getMessage().contains('Project cannot be closed with Open Milestones'));
}
Test.stopTest();
}
private static testMethod void validateOpenMilestoneTriggerPositive() {

//Setup the TestProject2 Record
pse__Proj__c p = new pse__Proj__c();
p.RecordTypeId = '012Z00000000JWKIA2';
p.Name='TestProject2';
p.pse__Region__c = 'a0wZ0000000WMArIAO';
p.pse__Is_Active__c = true;

insert p;

//Setup the Milestone2 Record
pse__Milestone__c m = new pse__Milestone__c();
m.Name = 'TestMileStone2';
m.pse__Project__c = p.ID;
m.pse__Milestone_Amount__c = 0;
m.pse__Target_Date__c = Date.today();
m.pse__Actual_Date__c = Date.today();

insert m;

Test.startTest();
//Set the milestone status to approved and the project to inactive
try
{
m.pse__Status__c = 'Approved';
p.pse__Is_Active__c = false;
}
Catch (System.DMLException e)
{
System.assert(e.getMessage().contains('Project can be closed if there are no Open Milestones'));
}
Test.stopTest();
}
private static testMethod void validateOpenMilestoneTriggerClosingProjects() {


//Setup the Project Record
pse__Proj__c p = new pse__Proj__c();
p.RecordTypeId = '012Z00000000JWKIA2';
p.Name='TestProject3';
p.pse__Region__c = 'a0wZ0000000WMArIAO';
p.pse__Is_Active__c = false;

pse__Proj__c p1 = new pse__Proj__c();
p1.RecordTypeId = '012Z00000000JWKIA2';
p1.Name='TestProject4';
p1.pse__Region__c = 'a0wZ0000000WMArIAO';
p1.pse__Is_Active__c = true;

insert p;
insert p1;
// Creates set of all active projects
set<id> closingprojects = new set<id>();

// sets the RecordTypeID for the Customer record and adds previous value to oldmap
if(p.RecordTypeId == '012Z00000000JWKIA2'&&(p.pse__Is_Active__c == false))
// Adds active projects to the closingprojects set
closingprojects.add(p.id);

Test.StartTest();
Try
{
if(p.RecordTypeId == '012Z00000000JWKIA2'&&(p.pse__Is_Active__c == false))
closingprojects.add(p.id);
}
Catch (System.DMLException e)
{
System.assertEquals(closingprojects.size(),1);
}
Test.StopTest();
}
}