//Functions to manage pop-ups

//Opens a pop-up window
function popwin(url,win,attribs) {
  if (typeof winpop == "undefined") {
    winpop=window.open(url,win,attribs);
  }else{
    if (winpop.closed) {
      winpop=window.open(url,win,attribs)
    }else{
      winpop.close(); winpop=window.open(url,win,attribs);
    }
  }
}

//opens a map as a pop-up for a quick look
function mapwin(url,win,attribs) {
  if (typeof winmap == "undefined") {
    winmap=window.open(url,win,attribs);
  }else{
    if (winmap.closed) {
      winmap=window.open(url,win,attribs)
    }else{
      winmap.close(); winmap=window.open(url,win,attribs);
    }
  }
}

//opens a figure pop-up for a quick look
function figwin(url,win,attribs) {
  if (typeof winfig == "undefined") {
    winfig=window.open(url,win,attribs);
  }else{
    if (winfig.closed) {
      winfig=window.open(url,win,attribs)
    }else{
      winfig.close(); winfig=window.open(url,win,attribs);
    }
  }
}

//closes the popups when the parent page is closed.
function closepops() { 
winpop.close();
winfig.close();
} 

//closes popup maps when the lesson using it is over.
function closemap() { 
winmap.close();
} 

//opens another pop-up for more information (used from pop-ups)
function newwin(url,win,attribs) {
  if (typeof _win == "undefined") {
    _win=window.open(url,win,attribs);
  }else{
    if (_win.closed) {
      _win=window.open(url,win,attribs)
    }else{
      _win.close(); _win=window.open(url,win,attribs);
    }
  }
}

//opens another pop-up for more information (used from pop-ups)
function newwin2(url,win,attribs) {
  if (typeof _win2 == "undefined") {
    _win2=window.open(url,win,attribs);
  }else{
    if (_win2.closed) {
      _win2=window.open(url,win,attribs)
    }else{
      _win2.close(); _win2=window.open(url,win,attribs);
    }
  }
}

//closes the extra pop-ups when the parent pop-up is closed.
function closemore() { 
_win.close(); 
_win2.close(); 
} 


//IMAGES
//Function to change images contained in layers
function changeimg(layername,imgname,imgsrc) {
	if (document.getElementById) {
		document.getElementById(imgname).src=imgsrc;
	} else if (document.layers)	{
	    document.layers[layername].document[imgname].src=imgsrc;
   	}else{
      document[imgname].src=imgsrc;
   	}
}