/* First thing is to declare global variables
   to contain the X and Y coordinates of the
   mouse cursor. */
var currentX = 0;
var currentY = 0;
	
/* Use "object sniffing" technique to determine
   if the browser has the captureEvent method.
   This tells us if the client is a Mozilla-type browser.
   If so, we tell the document object to 
   capture the MOUSEMOVE event. */
if (document.captureEvent){
  document.captureEvent(Event.MOUSEMOVE);
}
/* The getMousePosition() function will be the
event-handling function that sets
currentX and currentY. */
function getMousePosition(evt){

	/* Internet Explorer and Mozilla have differences
  both in the way they implement events and the
  way they determine x/y coordinates. */
  if (window.event){
    /* This is the Internet Explorer way.
    Adds the x and y coordinates relative to the screen
    to the number of pixels the user has scrolled 
    horizontally and vertically. */
    currentX = window.event.clientX + document.body.scrollLeft;
    currentY = window.event.clientY + document.body.scrollTop;
  }
  else if (evt){
    /* In Mozilla/Netscape browsers, you just need to access
    the pageX and pageY properties to determine coordinates. */
    currentX = evt.pageX;
    currentY = evt.pageY;
  }
}

// register getMousePosition() as an event handler for the onmousemove event.
document.onmousemove = getMousePosition;

/* The positionElement function will place an object
   at the coordinates (currentX+10, currentY+10).
   Parameter: any valid ID attribute of an element. */
function positionElement(id){
  // set elem to the element with specified id.
  elem = document.getElementById(id);
  if (elem){
    /* If the element exists, set the CSS style "left"
       to currentX + 10, and the CSS style "top" to
       currentY + 10. */
    elem.style.left = (currentX + 10) + "px";
    elem.style.top = (currentY + 10) + "px";
  }
}

/* hideToolTip will set the CSS "visibility" property to
   "hidden" for an element whose ID attribute is passed
   to the function. */
function hideToolTip(id){
  elem = document.getElementById(id);
  if (elem){
    elem.style.visibility="hidden";
  }
}

/* showToolTip will set the CSS "visibility" property to
   "visible" for an element whose ID attribute is passed
   to the function. */
function showToolTip(id){
  elem = document.getElementById(id);
  if (elem){
    elem.style.visibility="visible";
  }
}