errorMessageGridData.heightHint = convertHeightInCharsToPixels(2);
errorMessageText.setLayoutData(errorMessageGridData);
// now add the node type dropbox-combo
Label label = new Label(composite, SWT.WRAP);
label.moveAbove(errorMessageText);
label.setText("Define node type");
GridData data = new GridData(GridData.GRAB_HORIZONTAL
| GridData.GRAB_VERTICAL | GridData.HORIZONTAL_ALIGN_FILL
| GridData.VERTICAL_ALIGN_CENTER);
data.widthHint = convertHorizontalDLUsToPixels(IDialogConstants.MINIMUM_MESSAGE_AREA_WIDTH);