function getElementByClassName(clsName)
{
	var arr = new Array(); 
	var elems = document.getElementsByTagName("*");
	for ( var cls, i = 0, j = 0; ( elem = elems[i] ); i++ )
	{
		if ( elem.className == clsName )
		{
			arr[j++] = elem;
		}
	}

	return arr;
}


window.onload = function()
{
	var arr = getElementByClassName("photo_main");

	for(var i = 0; elem = arr[i]; i++)
	{
		elem.onmouseover = function()
		{
			this.childNodes.item(0).style.visibility = 'hidden';
		}

		elem.onmouseout = function()
		{
			this.childNodes.item(0).style.visibility = 'visible';
		}
	}
}