How to create Project Contract Id and Sub Project Id

void clicked()
{
    ProjTable                   projTable;
    ProjInvoiceTable            projInvoiceTable;
    ProjFundingSource           projFundingSource;
    ProjFundingRule             projFundingRule;
    ProjFundingRuleAllocation   projFundingRuleAllocation;
    NumberSeq                   numberSeq,numberSeqInv;
    // Sub project creation
    ProjTableType projTableType;
    NumberSeq projNumberSeq;
    ProjId projIdLastSon, projectId;
    ProjId projMask;
    Integer sonNum;
    str     a,b;

    ProjType _projType = ProjType::FixedPrice;
    ProjParentId _projParentId = UnitReservation_ProjId.valueStr(); // // project id here
    NumberSequenceFormat _numberSequenceMask;
    ProjLinePropertyId _projInvoiceStatusId;
    // Sub project
    UnitReservation        unitReservation1;

   
    super();
    ttsBegin;
    numberSeqInv = NumberSeq::newGetNum(ProjParameters::numRefProjInvoiceProjId());
    select forupdate projTable where projTable.ProjId == UnitReservation_ProjId.valueStr();//'MIPL-000025';
    {
        projTable.CustAccount = 'Cust Account';//UnitReservation_CustomerId.valueStr();
        //projTable.Name = CustTable::find(projTable.CustAccount).name();
        projInvoiceTable.ProjInvoiceProjId = numberSeqInv.num();
        projInvoiceTable.Description = 'name'//UnitReservation_PropertyName.valueStr(); //PropertyTable.Name;
        projInvoiceTable.CurrencyId = CompanyInfo::standardCurrency();

        projFundingSource.ContractId = projInvoiceTable.ProjInvoiceProjId;
        projFundingSource.FundingType = ProjFundingType::Customer;
        projFundingSource.CustAccount = 'Cust Account';//UnitReservation_CustomerId.valueStr();

        projFundingSource.editProjFunder(true,projFundingSource.CustAccount);

        projFundingSource.FundingSourceId = CustTable::find(projFundingSource.CustAccount).name();
        projFundingSource.LanguageId = 'en-in';
        projFundingRule.ContractId = projFundingSource.ContractId;
        projFundingRule.Priority = 1;
        projFundingRule.insert();
        projFundingSource.insert();

        projFundingRuleAllocation.AllocateRounding = NoYes::Yes;
        projFundingRuleAllocation.AllocationPercentage = 100;
        projFundingRuleAllocation.FundingRule = projFundingRule.RecId;
        projFundingRuleAllocation.FundingSource = projFundingSource.RecId;
        projFundingRuleAllocation.insert();
        projInvoiceTable.insert();
        projTable.ProjInvoiceProjId = projInvoiceTable.ProjInvoiceProjId;
        projTable.update();
    }
    ttsCommit;
    info(strFmt("Project contract Id '%1' has been created", projInvoiceTable.ProjInvoiceProjId));
    a = projInvoiceTable.ProjInvoiceProjId;
    // sub project code
    if (_projParentId)
    {
        projTable.type().initFromParent('Parent ProjId');//(UnitReservation_ProjId.valueStr());
        projIdLastSon = ProjTable::projIdLastSon(projTable.ParentId);

    if (projIdLastSon)
    {
        projMask = substr(projIdLastSon, strlen(projTable.ParentId) + 1, (strlen(projIdLastSon) - (strlen(projTable.ParentId)) + 1));
        sonNum = ProjTable::numRemTemplate(projMask, ProjTable::find(projTable.ParentId).Format);
    }

        projTable.ProjId = projTable.ParentId + NumberSeq::numInsertFormat(sonNum + 1, ProjTable::find(projTable.ParentId).Format);

    }
    else
    {
        projNumberSeq = NumberSeq::newGetNum(ProjParameters::numRefProjId(), true);

    if (projNumberSeq)
    {
        projTable.ProjId = projNumberSeq.num();
    }
    }
        projectId = projTable.ProjId;
        projTable.Type = ProjType::FixedPrice;//_projType;
        projTable.ProjGroupId = UnitReservation_ProjGroupId.valueStr();
     
        projTable.Name = _projName; //UnitReservation_CustName.valueStr();
        projTableType = projTable.type();

        projTableType.initProjTable();

        projTable.ProjInvoiceProjId = a; //_projInvoiceProjId;
        projInvoiceTable = ProjInvoiceTable::find(a);//_projInvoiceProjId);
        projTable.CustAccount = UnitReservation_CustomerId.valueStr(); //; //projInvoiceTable.InvoiceAccount;
        projTable.initFromInvoice(projInvoiceTable);
        projTable.Format = _numberSequenceMask;
        projTable.CheckBudget = ProjGroup::find(UnitReservation_ProjGroupId.valueStr()).CheckBudget;//_projGroupId).CheckBudget;
        projTable.Status = ProjStatus::InProcess;

    if (_projInvoiceStatusId)
    {
        ProjLinePropertySetup::updateLinePropertyProj(projTable.ProjId, _projInvoiceStatusId, TableGroupAll::Table, true);
    }

        projTable.initFromCustTable(CustTable::find(projTable.CustAccount));
    if (ProjTable::exist(projTable.ProjId))
    {
    // Project already exists.
        throw error('@SYS56494');
    }

    if (!projTableType.validateWrite())
        throw error ('Validations failed');

        projTable.insert();

    if (projNumberSeq)
    {
        projNumberSeq.used();
    }
    else
    {
        projTable.clear();

    if (projNumberSeq)
    {
        projNumberSeq.abort();
    }
    }

    //info (strfmt('Project %1 successfully created', projectId));
    b = projectId;
    // sub project code
    info(strFmt('%1',UnitReservation_ProjId.valueStr()));
     
}