private void multiplyActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_multiplyActionPerformed
        firstNum = (Double.parseDouble(String.valueOf(display.getText())));
        display.setText("");
        multiplyClick = 1;
        decimalClick = 0;        // TODO add your handling code here:
    }//GEN-LAST:event_multiplyActionPerformed