// Author: Matt Kruse <matt@mattkruse.com> http://www.mattkruse.com/

// 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=el.offsetTop;
    while((el=el.offsetParent) != null) { ot += el.offsetTop; }
    return ot;
    }
function AnchorPosition_getWindowOffsetTop (el) {
    return AnchorPosition_getPageOffsetTop(el)-document.body.scrollTop;
    }