var isNav4, isNav6, isIE4;

/*
 * Browser version snooper; determines your browser
 * (Navigator 4, Navigator 6, or Internet Explorer 4/5)
 */
function setBrowser()
{
    if (navigator.appVersion.charAt(0) == "4")
    {
        if (navigator.appName.indexOf("Explorer") >= 0)
        {
            isIE4 = true;
        }
        else
        {
            isNav4 = true;
        }
    }
    else if (navigator.appVersion.charAt(0) > "4")
    {
        isNav6 = true;
    }
}


function getStyleBySelector( selector )
{
    if (!isNav6)
    {
        return null;
    }
    var sheetList = document.styleSheets;
    var ruleList;
    var i, j;

    for (i=sheetList.length-1; i >= 0; i--)
    {
        ruleList = sheetList[i].cssRules;
        for (j=0; j<ruleList.length; j++)
        {
            if (ruleList[j].type == CSSRule.STYLE_RULE &&
                ruleList[j].selectorText == selector)
            {
                return ruleList[j].style;
            }   
        }
    }
    return null;
}

function getIdProperty( id, property )
{
    if (isNav6)
    {
        var styleObject = document.getElementById( id );
        if (styleObject != null)
        {
            styleObject = styleObject.style;
            if (styleObject[property])
            {
                return styleObject[ property ];
            }
        }
        styleObject = getStyleBySelector( "#" + id );
        return (styleObject != null) ?
            styleObject[property] :
            null;
    }
    else if (isNav4)
    {
        return document[id][property];
    }
    else
    {
        return document.all[id].style[property];
    }
}

function setIdProperty( id, property, value )
{
    if (isNav6)
    {
        var styleObject = document.getElementById( id );
        if (styleObject != null)
        {
            styleObject = styleObject.style;
            styleObject[ property ] = value;
        }
    }
    else if (isNav4)
    {
        document[id][property] = value;
    }
    else if (isIE4)
    {
         document.all[id].style[property] = value;
    }
}

function generic_move( id, xValue, yValue, additive )
{
    var left = getIdProperty(id, "left");
    var top = getIdProperty(id, "top");
    var leftMatch, topMatch;

    if (isNav4)
    {
        leftMatch = new Array( 0, left, "");
        topMatch = new Array( 0, top, "");
    }
    else if (isNav6 || isIE4 )
    {
        var splitexp = /([-0-9.]+)(\w+)/;
        leftMatch = splitexp.exec( left );
        topMatch = splitexp.exec( top );
        if (leftMatch == null || topMatch == null)
        {
            leftMatch = new Array(0, 0, "px");
            topMatch = new Array(0, 0, "px");
        }
    }
    left = ((additive) ? parseFloat( leftMatch[1] ) : 0) + xValue;
    top = ((additive) ? parseFloat( topMatch[1] ) : 0) + yValue;
    setIdProperty( id, "left", left + leftMatch[2] );
    setIdProperty( id, "top", top + topMatch[2] );
}

function moveIdTo( id, x, y )
{
    generic_move( id, x, y, false );
}

function moveIdBy( id, x, y)
{
    generic_move( id, x, y, true );
}

function hex( n )
{
    var hexdigits = "0123456789abcdef";
    return ( hexdigits.charAt(n >> 4) + hexdigits.charAt(n & 0x0f) );
}

function getBackgroundColor( id )
{
    var color;

    if (isNav4)
    {
        color = document[id].bgColor;
    }
    else if (isNav6)
    {
        var parseExp = /rgb.(\d+),(\d+),(\d+)./;
        var rgbvals;
        color = getIdProperty( id, "backgroundColor" );
        if (color)
        {
            rgbvals = parseExp.exec( color );
            if (rgbvals)
            {
                color = "#" + hex( rgbvals[1] ) + hex( rgbvals[2] ) +
                    hex( rgbvals[3] );
            }
        }
        return color;
    }
    else if (isIE4)
    {
        return document.all[id].backgroundColor;
    }
    return "";
}

function getDocument( divName )
{
    var doc;

    if (isNav4)
    {
        doc = window.document[divName].document;
    }
    else if (isNav6)
    {
        doc = document;
    }
    else if (isIE4)
    {
        doc = document;
    }
    return doc;
}

function swapDiv( divNum, expanding )
{
    if (expanding)
    {
        setIdProperty("c" + divNum, "display", "none");
        setIdProperty("e" + divNum, "display", "inline");
    }
    else
    {
        setIdProperty("e" + divNum, "display", "none");
        setIdProperty("c" + divNum, "display", "inline");
    }
}
setBrowser();