[Vulkan]

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      document.getElementById('menu').onmouseover=vipadaet();
      document.getElementById('menu').onmouseout=zapadaet();
	function vipadaet() {
	var vipadaet = document.getElementById('vipadaet')
		vipadaet.style.display = 'block'
	}
	function zapadaet() {
	var zapadaet = document.getElementById('vipadaet')
		zapadaet.style.display = 'none'
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<li id="menu"><a href="#" title="">vipadaet</a>

Про классы - да, блоги не врут. Метод действительно не кроссбраузерен.