I have a fairly simple Apex controller which I cannot figure out how to test.  I can't get above 57% code coverage.  I am not understanding something. Can someone please shed light. I do not have coverage for lines 15,16,17,18,19,20,21,23 Here is the code:

public class copyAddress {

P4_AssetDeploymentRelationship__c currentDeploy;

public copyAddress(ApexPages.StandardController controller) {
        this.currentDeploy = (P4_AssetDeploymentRelationship__c)controller.getRecord();
}

public PageReference address()
    {
        if (System.currentPageReference().getParameters().get('id')== null) {
        PageReference redraw = Apexpages.currentPage();
        ApexPages.addMessage(new ApexPages.Message(ApexPages.Severity.ERROR,'Parameter Does Not Exist'));
      return redraw; }
      string contactID = [select contact__c from P4_AssetDeploymentRelationship__c where id = :currentDeploy.Id].contact__c;     
      this.currentDeploy.Shipment_St_Address_1__c = [select mailingstreet from contact where id = :ContactID].mailingstreet;
      currentDeploy.Shipment_City__c = [select mailingcity from contact where id = :ContactID].mailingcity;
      currentDeploy.Shipment_State_Province__c = [select mailingstate from contact where id = :ContactID].mailingstate;
      currentDeploy.Shipment_Country__c = [select mailingcountry from contact where id = :ContactID].mailingcountry;
      currentDeploy.Shipment_Postal_Code__c  = [select mailingpostalcode from contact where id = :ContactID].mailingpostalcode;
      upsert currentDeploy;
      return null;
    }
 
    public PageReference persistAddress()
    {
       upsert currentDeploy;
       return null;
    }
    public static testMethod void testCopyAddress() {
    P4_AssetDeploymentRelationShip__c testDeploy = new P4_AssetDeploymentRelationShip__c();
    insert testDeploy;
    ApexPages.StandardController sc = new ApexPages.standardController(testDeploy);
    copyAddress testAddress = new copyAddress(sc);
    PageReference testPage = testAddress.Address();
    System.Assert(testPage != null);
    testPage = testAddress.persistAddress();
    System.AssertEquals(null,testPage);
    P4_AssetDeploymentRelationShip__c x;
    Contact c = new contact(FirstName='James',LastName='Malone',MailingStreet='8102 Dewberry Circle');
     insert c;
    testAddress.currentDeploy = new P4_AssetDeploymentRelationShip__c(contact__c=c.Id);
  
    insert testAddress.currentDeploy;   
       string contactID = [select contact__c from P4_AssetDeploymentRelationship__c where id = :testAddress.currentDeploy.Id].contact__c;     
       System.AssertEquals(testAddress.currentDeploy.contact__c, contactID);
     testAddress.currentDeploy.Shipment_St_Address_1__c = [select mailingstreet from contact where id = :ContactID].mailingstreet;
     upsert testAddress.currentDeploy;
     System.AssertEquals(c.MailingStreet,testAddress.currentDeploy.Shipment_St_Address_1__c);
     testAddress.currentDeploy.Shipment_State_Province__c = [select mailingstate from contact where id = :ContactID].mailingstate;
     upsert testAddress.currentDeploy;
      System.AssertEquals(c.MailingState,testAddress.currentDeploy.Shipment_State_Province__c);
}
}