//  From http://www.mattkruse.com/javascript/anchorposition/source.html
//  Tue May 29 18:52:09 CDT 2007
//  $Id: AnchorPosition.js,v 1.2 2007/05/29 23:54:30 nqa Exp $


// ===================================================================
// Author: Matt Kruse <matt@mattkruse.com>
// WWW: http://www.mattkruse.com/
//
// NOTICE: You may use this code for any purpose, commercial or
// private, without any further permission from the author. You may
// remove this notice from your final code if you wish, however it is
// appreciated by the author if at least my web site address is kept.
//
// You may *NOT* re-distribute this code in any way except through its
// use. That means, you can include it in your product, or your web
// site, or any other form where the code is actually being used. You
// may not put the plain javascript up on your site for download or
// include it in your javascript libraries for download. 
// If you wish to share this code with others, please just point them
// to the URL instead.
// Please DO NOT link directly to my .js files from your site. Copy
// the files to your server and use them there. Thank you.
// ===================================================================

/* 
   AnchorPosition.js
Author: Matt Kruse
Last modified: 10/11/02

DESCRIPTION: These functions find the position of an <A> tag in a document,
so other elements can be positioned relative to it.

COMPATABILITY: Netscape 4.x,6.x,Mozilla, IE 5.x,6.x on Windows. Some small
positioning errors - usually with Window positioning - occur on the 
Macintosh platform.

FUNCTIONS:
getAnchorPosition(anchorname)
Returns an Object() having .x and .y properties of the pixel coordinates
of the upper-left corner of the anchor. Position is relative to the PAGE.

getAnchorWindowPosition(anchorname)
Returns an Object() having .x and .y properties of the pixel coordinates
of the upper-left corner of the anchor, relative to the WHOLE SCREEN.

NOTES:

1) For popping up separate browser windows, use getAnchorWindowPosition. 
Otherwise, use getAnchorPosition

2) Your anchor tag MUST contain both NAME and ID attributes which are the 
same. For example:
<A NAME="test" ID="test"> </A>

3) There must be at least a space between <A> </A> for IE5.5 to see the 
anchor tag correctly. Do not do <A></A> with no space.
*/ 

// getAnchorPosition(anchorname)
//   This function returns an object having .x and .y properties which are the coordinates
//   of the named anchor, relative to the page.
function getAnchorPosition(anchorname) {
    // This function will return an Object with x and y properties
    var useWindow=false;
    var coordinates=new Object();
    var x=0,y=0;
    // Browser capability sniffing
    var use_gebi=false, use_css=false, use_layers=false;
    if (document.getElementById) { use_gebi=true; }
    else if (document.all) { use_css=true; }
    else if (document.layers) { use_layers=true; }
    // Logic to find position
    if (use_gebi && document.all) {
	x=AnchorPosition_getPageOffsetLeft(document.all[anchorname]);
	y=AnchorPosition_getPageOffsetTop(document.all[anchorname]);
    }
    else if (use_gebi) {
	var o=document.getElementById(anchorname);
	x=AnchorPosition_getPageOffsetLeft(o);
	y=AnchorPosition_getPageOffsetTop(o);
    }
    else if (use_css) {
	x=AnchorPosition_getPageOffsetLeft(document.all[anchorname]);
	y=AnchorPosition_getPageOffsetTop(document.all[anchorname]);
    }
    else if (use_layers) {
	var found=0;
	for (var i=0; i<document.anchors.length; i++) {
	    if (document.anchors[i].name==anchorname) { found=1; break; }
	}
	if (found==0) {
	    coordinates.x=0; coordinates.y=0; return coordinates;
	}
	x=document.anchors[i].x;
	y=document.anchors[i].y;
    }
    else {
	coordinates.x=0; coordinates.y=0; return coordinates;
    }
    coordinates.x=x;
    coordinates.y=y;
    return coordinates;
}

// getAnchorWindowPosition(anchorname)
//   This function returns an object having .x and .y properties which are the coordinates
//   of the named anchor, relative to the window
function getAnchorWindowPosition(anchorname) {
    var coordinates=getAnchorPosition(anchorname);
    var x=0;
    var y=0;
    if (document.getElementById) {
	if (isNaN(window.screenX)) {
	    x=coordinates.x-document.body.scrollLeft+window.screenLeft;
	    y=coordinates.y-document.body.scrollTop+window.screenTop;
	}
	else {
	    x=coordinates.x+window.screenX+(window.outerWidth-window.innerWidth)-window.pageXOffset;
	    y=coordinates.y+window.screenY+(window.outerHeight-24-window.innerHeight)-window.pageYOffset;
	}
    }
    else if (document.all) {
	x=coordinates.x-document.body.scrollLeft+window.screenLeft;
	y=coordinates.y-document.body.scrollTop+window.screenTop;
    }
    else if (document.layers) {
	x=coordinates.x+window.screenX+(window.outerWidth-window.innerWidth)-window.pageXOffset;
	y=coordinates.y+window.screenY+(window.outerHeight-24-window.innerHeight)-window.pageYOffset;
    }
    coordinates.x=x;
    coordinates.y=y;
    return coordinates;
}

// Functions for IE to get position of an object
function AnchorPosition_getPageOffsetLeft (el) {
    var ol=el.offsetLeft;
    while ((el=el.offsetParent) != null) { ol += el.offsetLeft; }
    return ol;
}
function AnchorPosition_getWindowOffsetLeft (el) {
    return AnchorPosition_getPageOffsetLeft(el)-document.body.scrollLeft;
}	
function AnchorPosition_getPageOffsetTop (el) {
    var ot=0; //aqn el.offsetTop;
    while((el=el.offsetParent) != null) { ot += el.offsetTop; }
    return ot;
}
function AnchorPosition_getWindowOffsetTop (el) {
    return AnchorPosition_getPageOffsetTop(el)-document.body.scrollTop;
}




function scrollToAnchor(anchorname)
{
    var coordinates = getAnchorPosition(anchorname);
    window.scrollTo(coordinates.x, coordinates.y);
}