var undefined;
function IsUndefined(v) { return (v == undefined); }
function IsEmptyString(v) { return (v == undefined || v === ""); }
function IsEmpty(v) { try {	return (v == undefined || v == null || v === ""); } catch (e) {	return false; } }

function SwapChess(img, src, bottom)
{
	if (src != null)
	{
		img.src = "../images/"+ src;
		document.getElementById("ChessBottom").src = "../images/"+ bottom; 
	}
}

function SwapAll(i, bottom)
{
	var img;
	var target;
	for (var r=0; r<3; r++)
	{
		for (var c=0; c<6; c++)
		{
			if (i==0)
				document.getElementById('Chess_'+ r +'_'+ c +"_idIMG").onmouseout();
			else
				document.getElementById('Chess_'+ r +'_'+ c +"_idIMG").onmouseover();
		}
	}
	document.getElementById("ChessBottom").src = "../images/"+ bottom; 
}