var n = 4;
var f = false;
var b = new Array;
var b1 = new Array;

function prel()
{
	if (document.images)
	{
		for (i = 0; i < n; i++)
		{
			var index = i + 1;

			str = '/images/buttons/p' + index + '_ru_o.gif';
			b[i] = new Image();
			b[i].src = str;
			
			str1 = '/images/buttons/p' + index + '_en_o.gif';
			b1[i] = new Image();
			b1[i].src = str1;
		}
		
		f = true;
	}
}

function on(im)
{
	if (document.images && f == true)
		document[im].src = "/images/buttons/" + im + "_o.gif";
}

function off(im)
{
	if (document.images && f == true)
		document[im].src = "/images/buttons/" + im + ".gif";
}