InventTable form selection open new form filtered on selection

I have a form that gets all SalesLines that have "back ordered" items. I use a temp table to get that done and it works fine. I would like to go to an ItemID on the InventTable, then click a button to open this form filtered on that ItemID. I've looked at other forms that are set up like this, but I'm not getting anywhere. Need a little push. Here's the code I have right now. I created a TempTable with some fields and used that as my data source, then populated it.

public void init()
{

super();
this.getBackorders();

}

void getBackorders()
{

    SalesTable              salesTable;
    SalesLine               salesLine;
    pjpTestTempTable        salesLinetmp;
    Counter                 recordsFound;
    ;

    salesLinetmp.setTmp();

    while select * from salesTable
        join salesLine
        where salesTable.SalesId == salesLine.SalesId
           && salesTable.SalesStatus == SalesStatus::Backorder
    {

        if(salesLine.mbsBackOrderLinesTotal() > 0 )
        {

            salesLinetmp.Itemid = salesLine.ItemID;
            salesLinetmp.ItemName = salesLine.SalesID;
            salesLinetmp.BackOrders = salesLine.mbsBackOrderLinesTotal();

            salesLinetmp.doInsert();

        }

        pjpTestTempTable.setTmp();
        pjpTestTempTable.setTmpData(salesLinetmp);

    }

}