public String open() {
    Shell parent = getParent();
    Display display = parent.getDisplay();

    shell = new Shell(parent, SWT.DIALOG_TRIM | SWT.RESIZE | SWT.MIN | SWT.MAX);
    props.setLook(shell);
    setShellImage(shell, input);

    ModifyListener lsMod =
        new ModifyListener() {
          public void modifyText(ModifyEvent e) {
            input.setChanged();
          }
        };
    backupChanged = input.hasChanged();

    FormLayout formLayout = new FormLayout();
    formLayout.marginWidth = Const.FORM_MARGIN;
    formLayout.marginHeight = Const.FORM_MARGIN;

    shell.setLayout(formLayout);
    shell.setText(BaseMessages.getString(PKG, "MergeRowsDialog.Shell.Label"));

    int middle = props.getMiddlePct();
    int margin = Const.MARGIN;

    // Stepname line
    wlStepname = new Label(shell, SWT.RIGHT);
    wlStepname.setText(BaseMessages.getString(PKG, "MergeRowsDialog.Stepname.Label"));
    props.setLook(wlStepname);
    fdlStepname = new FormData();
    fdlStepname.left = new FormAttachment(0, 0);
    fdlStepname.right = new FormAttachment(middle, -margin);
    fdlStepname.top = new FormAttachment(0, margin);
    wlStepname.setLayoutData(fdlStepname);
    wStepname = new Text(shell, SWT.SINGLE | SWT.LEFT | SWT.BORDER);
    wStepname.setText(stepname);
    props.setLook(wStepname);
    wStepname.addModifyListener(lsMod);
    fdStepname = new FormData();
    fdStepname.left = new FormAttachment(middle, 0);
    fdStepname.top = new FormAttachment(0, margin);
    fdStepname.right = new FormAttachment(100, 0);
    wStepname.setLayoutData(fdStepname);

    // Get the previous steps...
    String[] previousSteps = transMeta.getPrevStepNames(stepname);

    // Send 'True' data to...
    wlReference = new Label(shell, SWT.RIGHT);
    wlReference.setText(BaseMessages.getString(PKG, "MergeRowsDialog.Reference.Label"));
    props.setLook(wlReference);
    fdlReference = new FormData();
    fdlReference.left = new FormAttachment(0, 0);
    fdlReference.right = new FormAttachment(middle, -margin);
    fdlReference.top = new FormAttachment(wStepname, margin);
    wlReference.setLayoutData(fdlReference);
    wReference = new CCombo(shell, SWT.BORDER);
    props.setLook(wReference);

    if (previousSteps != null) {
      wReference.setItems(previousSteps);
    }

    wReference.addModifyListener(lsMod);
    fdReference = new FormData();
    fdReference.left = new FormAttachment(middle, 0);
    fdReference.top = new FormAttachment(wStepname, margin);
    fdReference.right = new FormAttachment(100, 0);
    wReference.setLayoutData(fdReference);

    // Send 'False' data to...
    wlCompare = new Label(shell, SWT.RIGHT);
    wlCompare.setText(BaseMessages.getString(PKG, "MergeRowsDialog.Compare.Label"));
    props.setLook(wlCompare);
    fdlCompare = new FormData();
    fdlCompare.left = new FormAttachment(0, 0);
    fdlCompare.right = new FormAttachment(middle, -margin);
    fdlCompare.top = new FormAttachment(wReference, margin);
    wlCompare.setLayoutData(fdlCompare);
    wCompare = new CCombo(shell, SWT.BORDER);
    props.setLook(wCompare);

    if (previousSteps != null) {
      wCompare.setItems(previousSteps);
    }

    wCompare.addModifyListener(lsMod);
    fdCompare = new FormData();
    fdCompare.top = new FormAttachment(wReference, margin);
    fdCompare.left = new FormAttachment(middle, 0);
    fdCompare.right = new FormAttachment(100, 0);
    wCompare.setLayoutData(fdCompare);

    // Stepname line
    wlFlagfield = new Label(shell, SWT.RIGHT);
    wlFlagfield.setText(BaseMessages.getString(PKG, "MergeRowsDialog.FlagField.Label"));
    props.setLook(wlFlagfield);
    fdlFlagfield = new FormData();
    fdlFlagfield.left = new FormAttachment(0, 0);
    fdlFlagfield.right = new FormAttachment(middle, -margin);
    fdlFlagfield.top = new FormAttachment(wCompare, margin);
    wlFlagfield.setLayoutData(fdlFlagfield);
    wFlagfield = new Text(shell, SWT.SINGLE | SWT.LEFT | SWT.BORDER);
    props.setLook(wFlagfield);
    wFlagfield.addModifyListener(lsMod);
    fdFlagfield = new FormData();
    fdFlagfield.top = new FormAttachment(wCompare, margin);
    fdFlagfield.left = new FormAttachment(middle, 0);
    fdFlagfield.right = new FormAttachment(100, 0);
    wFlagfield.setLayoutData(fdFlagfield);

    // THE KEYS TO MATCH...
    wlKeys = new Label(shell, SWT.NONE);
    wlKeys.setText(BaseMessages.getString(PKG, "MergeRowsDialog.Keys.Label"));
    props.setLook(wlKeys);
    fdlKeys = new FormData();
    fdlKeys.left = new FormAttachment(0, 0);
    fdlKeys.top = new FormAttachment(wFlagfield, margin);
    wlKeys.setLayoutData(fdlKeys);

    int nrKeyRows = (input.getKeyFields() != null ? input.getKeyFields().length : 1);

    ColumnInfo[] ciKeys =
        new ColumnInfo[] {
          new ColumnInfo(
              BaseMessages.getString(PKG, "MergeRowsDialog.ColumnInfo.KeyField"),
              ColumnInfo.COLUMN_TYPE_TEXT,
              false),
        };

    wKeys =
        new TableView(
            transMeta,
            shell,
            SWT.BORDER | SWT.FULL_SELECTION | SWT.MULTI | SWT.V_SCROLL | SWT.H_SCROLL,
            ciKeys,
            nrKeyRows,
            lsMod,
            props);

    fdKeys = new FormData();
    fdKeys.top = new FormAttachment(wlKeys, margin);
    fdKeys.left = new FormAttachment(0, 0);
    fdKeys.bottom = new FormAttachment(100, -70);
    fdKeys.right = new FormAttachment(50, -margin);
    wKeys.setLayoutData(fdKeys);

    wbKeys = new Button(shell, SWT.PUSH);
    wbKeys.setText(BaseMessages.getString(PKG, "MergeRowsDialog.KeyFields.Button"));
    fdbKeys = new FormData();
    fdbKeys.top = new FormAttachment(wKeys, margin);
    fdbKeys.left = new FormAttachment(0, 0);
    fdbKeys.right = new FormAttachment(50, -margin);
    wbKeys.setLayoutData(fdbKeys);
    wbKeys.addSelectionListener(
        new SelectionAdapter() {

          public void widgetSelected(SelectionEvent e) {
            getKeys();
          }
        });

    // VALUES TO COMPARE
    wlValues = new Label(shell, SWT.NONE);
    wlValues.setText(BaseMessages.getString(PKG, "MergeRowsDialog.Values.Label"));
    props.setLook(wlValues);
    fdlValues = new FormData();
    fdlValues.left = new FormAttachment(50, 0);
    fdlValues.top = new FormAttachment(wFlagfield, margin);
    wlValues.setLayoutData(fdlValues);

    int nrValueRows = (input.getValueFields() != null ? input.getValueFields().length : 1);

    ColumnInfo[] ciValues =
        new ColumnInfo[] {
          new ColumnInfo(
              BaseMessages.getString(PKG, "MergeRowsDialog.ColumnInfo.ValueField"),
              ColumnInfo.COLUMN_TYPE_TEXT,
              false),
        };

    wValues =
        new TableView(
            transMeta,
            shell,
            SWT.BORDER | SWT.FULL_SELECTION | SWT.MULTI | SWT.V_SCROLL | SWT.H_SCROLL,
            ciValues,
            nrValueRows,
            lsMod,
            props);

    fdValues = new FormData();
    fdValues.top = new FormAttachment(wlValues, margin);
    fdValues.left = new FormAttachment(50, 0);
    fdValues.bottom = new FormAttachment(100, -70);
    fdValues.right = new FormAttachment(100, 0);
    wValues.setLayoutData(fdValues);

    wbValues = new Button(shell, SWT.PUSH);
    wbValues.setText(BaseMessages.getString(PKG, "MergeRowsDialog.ValueFields.Button"));
    fdbValues = new FormData();
    fdbValues.top = new FormAttachment(wValues, margin);
    fdbValues.left = new FormAttachment(50, 0);
    fdbValues.right = new FormAttachment(100, 0);
    wbValues.setLayoutData(fdbValues);
    wbValues.addSelectionListener(
        new SelectionAdapter() {

          public void widgetSelected(SelectionEvent e) {
            getValues();
          }
        });

    // Some buttons
    wOK = new Button(shell, SWT.PUSH);
    wOK.setText(BaseMessages.getString(PKG, "System.Button.OK"));
    wCancel = new Button(shell, SWT.PUSH);
    wCancel.setText(BaseMessages.getString(PKG, "System.Button.Cancel"));

    setButtonPositions(new Button[] {wOK, wCancel}, margin, wbKeys);

    // Add listeners
    lsCancel =
        new Listener() {
          public void handleEvent(Event e) {
            cancel();
          }
        };
    lsOK =
        new Listener() {
          public void handleEvent(Event e) {
            ok();
          }
        };

    wCancel.addListener(SWT.Selection, lsCancel);
    wOK.addListener(SWT.Selection, lsOK);

    lsDef =
        new SelectionAdapter() {
          public void widgetDefaultSelected(SelectionEvent e) {
            ok();
          }
        };

    wStepname.addSelectionListener(lsDef);

    // Detect X or ALT-F4 or something that kills this window...
    shell.addShellListener(
        new ShellAdapter() {
          public void shellClosed(ShellEvent e) {
            cancel();
          }
        });

    // Set the shell size, based upon previous time...
    setSize();

    getData();
    input.setChanged(backupChanged);

    shell.open();
    while (!shell.isDisposed()) {
      if (!display.readAndDispatch()) {
        display.sleep();
      }
    }
    return stepname;
  }
 private void cancel() {
   stepname = null;
   input.setChanged(backupChanged);
   dispose();
 }