(function(){
   $( document ).ready(function() {
		// Find every element with class .pick-kolumn
		$('.pick-kolumn').click(function() {
			// Find index number from attribute data-column found on the button
			var columnIndex = $(this).attr('data-column');
			// For loop for each element that has a class of .kolumna
			$('.column').each(function(index, element) {
				var $element = $(element);
				// Remove all column-chosen classes from .kolumna
				$element.removeClass('column-chosen');
				// Each element in the loop has an index attribute, we check here if
				// the index of the element matches the one from the data-attribute if yes
				// we add .column-chosen
				// index is a number and columnIndex is a string so we need to convert
				// the number to a string to check for equality
				if (index.toString() === columnIndex) {
					$element.addClass('column-chosen');
				}
			})
		})
	})
})()