//if user click the button add
		if(e.getSource() == btnAdd) {
			//here we get the inputed value from the user and store it in variable
			String fname  = txtFirstname.getText();
			String lname  = txtLastname.getText();
			String email = txtEmail.getText();
			String pass = String.valueOf(txtPassword.getPassword());
			String yearLvl = cbxYearLvl.getSelectedItem().toString();

			//this first if statement will check if the user leave an empty field
			if(fname.isEmpty() || lname.isEmpty() || email.isEmpty() || pass.isEmpty()) {
				//this message dialog will appear once the user don't fill a field
				JOptionPane.showMessageDialog(this, "Please fill up all field", "Try again", JOptionPane.ERROR_MESSAGE);
			} else {
				//here we create instance of DefaultTableModel to store inputed value from user to the cell.
				DefaultTableModel tableModel = (DefaultTableModel) tableData.getModel();
				tableModel.addRow(new Object[] {fname,lname,email,pass,yearLvl});
				//And in this line will simply reset the fields empty after clicking the add button
				txtFirstname.setText("");
				txtLastname.setText("");
				txtEmail.setText("");
				txtPassword.setText("");
				cbxYearLvl.setSelectedIndex(0);
			}
		}
		if(e.getSource() == btnDelete) {
			int selectedRow = tableData.getSelectedRow();

			if(selectedRow < 0) {
				JOptionPane.showMessageDialog(this, "No row is selected! Please select one row", "Select row", JOptionPane.ERROR_MESSAGE);
			} else {
				DefaultTableModel tableModel = (DefaultTableModel) tableData.getModel();
				tableModel.removeRow(selectedRow);
			}
		}