private void jComboBox1ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jComboBox1ActionPerformed
      selecciono = jComboBox1.getSelectedIndex();
      if(selecciono ==1)
          jTextField1.setText("SELECT *FROM JCOV_CLIENTES");
      if(selecciono ==2)
          jTextField1.setText("SELECT *FROM JCOV_DETALLES");
      if(selecciono ==3)
          jTextField1.setText("SELECT *FROM JCOV_FACTURAS");
      
    }//GEN-LAST:event_jComboBox1ActionPerformed