Action goToLine = new Action(){
@Override
public void run() {
if(shellGoToLine==null || shellGoToLine.isDisposed()){
GoToLine gotoLine= new GoToLine();
shellGoToLine=gotoLine.getShell();
gotoLine.show();
}
else{
shellGoToLine.setVisible(true);
shellGoToLine.setFocus();
}