private boolean validarCampos(){
        boolean error= false;
        if(txtNum.getText().isEmpty()){
            txtNum.setBorder(javax.swing.BorderFactory.createEtchedBorder(Color.lightGray, Color.red));
            txtNum.setToolTipText("Por favor digite el numero de factura.");
            error= true; 
        }
        if(dcFecha.getDate()== null){
            error= true; 
        }
        if(txtRif.getText().equals(" -        - ")){
            txtRif.setBorder(javax.swing.BorderFactory.createEtchedBorder(Color.lightGray, Color.red));
            txtRif.setToolTipText("Por favor digite el RIF del cliente.");
            error= true;
        }
        if(txtRS.getText().isEmpty()){
            txtRS.setBorder(javax.swing.BorderFactory.createEtchedBorder(Color.lightGray, Color.red));
            txtRS.setToolTipText("Por favor digite la Razón social o Nombre del Cliente");
            error= true;
        }
        if(txtDir.getText().isEmpty()){
            txtDir.setBorder(javax.swing.BorderFactory.createEtchedBorder(Color.lightGray, Color.red));
            txtDir.setToolTipText("Por favor digite la Dirección del Cliente");
            error= true;
        }
        
        if(error)
            JOptionPane.showMessageDialog(this, "Por favor verifique que esten todos los campos completos");
        
        return error;
    }