Selecting items from different form and display in salesline form

To add new button in salestable form-> Linesview -> to show all related items based on salestable itemtype. And selecting items in other form and need to display in salesline:

1. Create new form(INC_InventItemsdetails) by taking InventTable datasource and adding Display           menuitem (Inventitemdetailsdisplay).
2. Add menuitembutton in salesline, provide display menuitem(Inventitemdetailsdisplay).
3. In Form = INC_InventTabledetails -> Form ->Init()
    public void init()
 {
    SalesTable      salesTable;
    super();
    salesTable  =   element.args().record();
                I               InventTable_ds.query().dataSourceTable(Tablenum(InventTable)).addRange(fieldNum(InventTable,I    NC_ItemType)).value(SysQuery::value(salesTable.INC_ItemType));
}
4. Taking command button in INC_InventTabledetails form -> Clicked()
void clicked()
{
    SalesLine       salesLine;
    SalesTable      salesTable;
    int             recordsCount;
    InventTable     inventTableloc;
    AxSalesLine     axSalesLine;
    Object          _fds;

    super();
    salesTable  =   element.args().record();
    _fds        =   element.args().record().dataSource();

    recordsCount = InventTable_ds.recordsMarked().lastIndex();  // Total number of marked records.
    inventTableloc = InventTable_ds.getFirst(1);

    while (inventTableloc)
    {
        salesLine.clear();
        salesLine.initFromSalesTable(salesTable);
        axSalesLine = AxSalesLine::newSalesLine(salesLine);
        axSalesLine.parmSalesId(salesTable.SalesId);
        axSalesLine.parmItemId(inventTableloc.ItemId);
        axSalesLine.parmSalesQty(1);
        axSalesLine.save();
        inventTableloc =   InventTable_ds.getNext();
    }
    _fds.reReadLines();
}