hello everyone...
i've got a QWidget application to convert from decimal to binary.
i just don't understand why this error keeps appearing in the console:
QObject::connect: No such slot QLabel::__dec2bin_()
why is this happening?
here's all the contents (the project is called NSC):

nsc.h:
Qt Code: 
  1. #ifndef NSC_H
  2. #define NSC_H
  3.  
  4. #include <QWidget>
  5. #include <QMainWindow>
  6. #include <Qt>
  7. #include <QLabel>
  8. #include <QLineEdit>
  9. #include <QCommandLinkButton>
  10. #include <QScrollArea>
  11. #include <QVBoxLayout>
  12.  
  13. namespace Ui {
  14. class NSC;
  15. }
  16.  
  17. class NSC : public QWidget
  18. {
  19.     Q_OBJECT
  20.  
  21. public:
  22.     explicit NSC(QWidget *parent = 0);
  23.     ~NSC();
  24.  
  25.     QLabel *title;
  26.     QLineEdit *decimal_entry;
  27.     QCommandLinkButton *dec2bin;
  28.     QCommandLinkButton *dec2oct;
  29.     QCommandLinkButton *dec2hex;
  30.     QLabel *result;
  31.     QLabel *footer;
  32.     QVBoxLayout *layout;
  33.     QWidget *mainWindow;
  34.  
  35. public slots:
  36.     void __dec2bin_();
  37.  
  38. private:
  39.     Ui::NSC *ui;
  40. };
  41.  
  42. #endif // NSC_H
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main.cpp:
Qt Code: 
  1. #include "nsc.h"
  2. #include <QApplication>
  3. #include <QWidget>
  4. #include <QMainWindow>
  5. #include <Qt>
  6. #include <QLabel>
  7. #include <QLineEdit>
  8. #include <QCommandLinkButton>
  9. #include <QScrollArea>
  10. #include <QVBoxLayout>
  11.  
  12.  
  13. int main(int argc, char *argv[])
  14. {
  15.     QApplication a(argc, argv);
  16.  
  17.     QLabel *title=new QLabel;
  18.     title->setGeometry(0,0,400,30);
  19.     title->setStyleSheet("font-size:20px;");
  20.     title->setAlignment(Qt::AlignHCenter | Qt::AlignVCenter);
  21.     title->setText("Numerical Systems Converter");
  22.  
  23.     QLineEdit *decimal_entry=new QLineEdit;
  24.     decimal_entry->setGeometry(0,50,400,30);
  25.     decimal_entry->setClearButtonEnabled(true);
  26.     decimal_entry->setStyleSheet("font-size:20px;");
  27.     decimal_entry->setAlignment(Qt::AlignHCenter | Qt::AlignVCenter);
  28.     decimal_entry->setPlaceholderText("Enter Your Decimal Number Here...");
  29.  
  30.     QCommandLinkButton *dec2bin=new QCommandLinkButton;
  31.     dec2bin->setGeometry(0,90,400,50);
  32.     dec2bin->setStyleSheet("font-size:20px;");
  33.     dec2bin->setText("Convert To Binary");
  34.  
  35.     QLabel *result=new QLabel;
  36.     result->setGeometry(0,250,400,30);
  37.     result->setStyleSheet("font-size:20px;");
  38.     result->setAlignment(Qt::AlignHCenter | Qt::AlignVCenter);
  39.     result->setText("The Result Should Appear Here...");
  40.  
  41.     QLabel *footer=new QLabel;
  42.     footer->setGeometry(0,300,400,80);
  43.     footer->setStyleSheet("font-size:20px;");
  44.     footer->setAlignment(Qt::AlignHCenter | Qt::AlignVCenter);
  45.     footer->setText("Designed And Programmed By:<br> <a href='http://www.facebook.com/eyad.syrialover'>Syrian Lucianos</a>");
  46.     footer->setTextFormat(Qt::RichText);
  47.     footer->setTextInteractionFlags(Qt::TextBrowserInteraction);
  48.     footer->setOpenExternalLinks(true);
  49.  
  50.     QVBoxLayout *layout=new QVBoxLayout;
  51.     layout->addWidget(title);
  52.     layout->addWidget(decimal_entry);
  53.     layout->addWidget(dec2bin);
  54.     layout->addWidget(result);
  55.     layout->addWidget(footer);
  56.  
  57.     QWidget *mainWindow=new QWidget;
  58.     mainWindow->setLayout(layout);
  59.     mainWindow->setFixedSize(400,400);
  60.  
  61.     QObject::connect(dec2bin,SIGNAL(clicked()),result,SLOT(__dec2bin_()));
  62.  
  63.     mainWindow->show();
  64.  
  65.     return a.exec();
  66. }
  67.  
  68. void NSC::__dec2bin_() {
  69.     QString dec2bin_result="";
  70.     for (int i=(decimal_entry->text()).toInt();i>0;i=i/2) {
  71.         dec2bin_result.prepend(QString::number(i%2));
  72.     }
  73.     result->setText(dec2bin_result);
  74. }
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nsc.cpp:
Qt Code: 
  1. #include "nsc.h"
  2. #include "ui_nsc.h"
  3.  
  4. NSC::NSC(QWidget *parent) :
  5.     QWidget(parent),
  6.     ui(new Ui::NSC)
  7. {
  8.     ui->setupUi(this);
  9. }
  10.  
  11. NSC::~NSC()
  12. {
  13.     delete ui;
  14. }
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thanks in advance