BSUIR sort schedule

sort.js

function sortSchedule(event) {
    let tableSchedule = document.querySelector('table.scheduleStyle'),
        subjects = tableSchedule.querySelectorAll('tr.ui-widget-content');
	
	event.preventDefault();
    for (let row of subjects) {
        if (row.getElementsByTagName('td')[0].style.backgroundColor == 'rgb(255, 216, 218)') { 
            row.style.display = 'none';
        }
    }
}

(function() {
	let sortButton = document.createElement('button'),
        buttonsBlock = document.querySelector('div.semesterBlock'),
        spanIcon = document.createElement('span'),
        spanText = document.createElement('span');

    sortButton.classList.add('ui-button', 'ui-widget', 'ui-state-default', 'ui-corner-all', 'ui-button-text-icon-left', 'printReport');
    spanIcon.classList.add('ui-button-icon-left', 'ui-icon', 'ui-c', 'ui-icon-print');
    spanText.classList.add('ui-button-text', 'ui-c');
    spanIcon.style.backgroundPosition = '-175px -111px';
    spanText.innerText = 'Отсортировать';
    sortButton.onclick = sortSchedule;

    sortButton.appendChild(spanIcon);
    sortButton.appendChild(spanText);

    buttonsBlock.appendChild(sortButton);
})();

Formating