private void btnSubmitActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_btnSubmitActionPerformed
        // TODO add your handling code here:
        if (currentBid > 0)
        {
            if (isInteger(tfBidderID.getText()))
            {
                currentPrice += currentBid;
                currentPriceLabel.setText("$"+currentPrice+".00");
                highestBidder = Integer.parseInt(tfBidderID.getText());
                lbHighBidder.setText("Highest Bidder: "+ highestBidder);
                // reset
                currentBid = 0;
                btnSubmit.setEnabled(false);
                tfBidderID.setEnabled(false);
                tfBidderID.setText("ID");
                resetBtnPlacementColor();
            }
            else
            {
                if (tfBidderID.getText().equals(""))
                {
                    JOptionPane.showMessageDialog(this, "Bidder ID is required.");
                }
                else
                {
                    JOptionPane.showMessageDialog(this, "Bidder ID must be a number.");
                }
                
            }
        }
    }//GEN-LAST:event_btnSubmitActionPerformed