<div id="page">
<li><label for="ch_effects">Пролонгация: </label><input type="checkbox"  id="ch_effects" name="ch_effects" data-on="Да" data-off="Нет" /></li>
</div>

(function($){
	$.fn.tzCheckbox = function(options){
		// Default On / Off labels:
		
		options = $.extend({
			labels : ['ON','OFF']
		},options);
		
		return this.each(function(){
			var originalCheckBox = $(this),
				labels = [];

			// Checking for the data-on / data-off HTML5 data attributes:
			if(originalCheckBox.data('on')){
				labels[0] = originalCheckBox.data('on');
				labels[1] = originalCheckBox.data('off');
			}
			else labels = options.labels;

			// Creating the new checkbox markup:
			var checkBox = $('<span>',{
				className	: 'tzCheckBox '+(this.checked?'checked':''),
				html:	'<span class="tzCBContent">'+labels[this.checked?0:1]+
						'</span><span class="tzCBPart"></span>'
			});

			// Inserting the new checkbox, and hiding the original:
			checkBox.insertAfter(originalCheckBox.hide());

			checkBox.click(function(){
				checkBox.toggleClass('checked');
				var isChecked = checkBox.hasClass('checked');
				
				// Synchronizing the original checkbox:
				originalCheckBox.attr('checked',isChecked);
				checkBox.find('.tzCBContent').html(labels[isChecked?0:1]);
			});
			
			// Listening for changes on the original and affecting the new one:
			originalCheckBox.bind('change',function(){

				checkBox.click();
			});
		});
	};
})(jQuery);

<div id="page">
	<li>
		<label for="ch_effects">Пролонгация: </label>
		<input type="checkbox"  id="ch_effects" name="ch_effects" data-on="Да" data-off="Нет" />
	</li>
	<button onclick='test();'>Test</button>
</div>
<script type='text/javascript'>
function test(){
	alert(document.getElementById('ch_effects').checked);
};
</script>