public function start() {
        $ci = 0;
        echo '<table id="uuresults" class="generaltable boxaligncenter flexible-wrap" summary="'.get_string('uploadusersresult', 'tool_uploaduser').'">';
        echo '<tr class="heading r0">';
        echo '<th class="header c'.$ci++.'" scope="col">'.get_string('status').'</th>';
        echo '<th class="header c'.$ci++.'" scope="col">'.get_string('uucsvline', 'tool_uploaduser').'</th>';
        echo '<th class="header c'.$ci++.'" scope="col">ID</th>';
        echo '<th class="header c'.$ci++.'" scope="col">'.get_string('username').'</th>';
        echo '<th class="header c'.$ci++.'" scope="col">'.get_string('firstname').'</th>';
        echo '<th class="header c'.$ci++.'" scope="col">'.get_string('lastname').'</th>';
        echo '<th class="header c'.$ci++.'" scope="col">'.get_string('email').'</th>';
        echo '<th class="header c'.$ci++.'" scope="col">'.get_string('password').'</th>';
        echo '<th class="header c'.$ci++.'" scope="col">'.get_string('authentication').'</th>';
        echo '<th class="header c'.$ci++.'" scope="col">'.get_string('enrolments', 'enrol').'</th>';
        echo '<th class="header c'.$ci++.'" scope="col">'.get_string('suspended', 'auth').'</th>';
        echo '<th class="header c'.$ci++.'" scope="col">'.get_string('delete').'</th>';
        echo '</tr>';
        $this->_row = null;
    }