function left(str, n){
	if (n <= 0) return "";
	else if (n > String(str).length) return str;
	else return String(str).substring(0,n);
}
function right(str, n){
	if (n <= 0) return "";
	else if (n > String(str).length) return str;
	else {
		var iLen = String(str).length;
		return String(str).substring(iLen, iLen - n);
	}
}

function Position(ElementID){
	Item = eval(right(ElementID, 2));
	if(document.getElementById){
		var x,y,r,vgap,nItems = new Number();
		ElementID = document.getElementById(ElementID);
		vgap = 22.75;
		nItems = 10;
		x = (Item - 1) * vgap;
		r = (nItems - 1) * vgap / 2;
		y = r * Math.sin(Math.acos((r - x) / r));
		//window.alert(r + " - " + x + "/" + r + " = " + ((r - x ) / r));
		ElementID.style.top = Math.round(x).toString() + 'px';
		ElementID.style.left = Math.round(y).toString() + 'px';
		//window.alert(ElementID.style.top);
	} else {
		window.alert('Your internet browser doesn\'t support DOM Level 1 specification,\n please try to upgrade to a newer version as soon as possible');
	}
}


function PositionAll(ElementID_1,ElementID_2){
	Item_1 = eval(right(ElementID_1, 2));
	Item_2 = eval(right(ElementID_2, 2));
	for (i=Item_1; i<=Item_2; i++){
			if (i< 10) {
				ElementID = 'Img_0' + i.toString();
			}
			else{
				ElementID = 'Img_' + i.toString();
			}
			Position(ElementID);
	}
}

function ChangeVisibilityOf(ElementID){
	if (document.getElementById){
		//MyElementID = ElementID;
		ElementID = document.getElementById(ElementID);
		//status = ElementID.style.display;
		if (ElementID.style.display == 'none' | ElementID.style.display == '') {
			//Position(MyElementID);
			ElementID.style.display = 'block';
		}else {
			ElementID.style.display = 'none';
		}
	}else{
		window.alert('Your internet browser doesn\'t support DOM Level 1 specification,\n please try to upgrade to a newer version as soon as possible');
	}
}