var layerobject = ((document.layers) ? (true) : (false));
var dom = ((document.getElementById) ? (true) : (false));
var allobject = ((document.all) ? (true) : (false));

opera = navigator.userAgent.toLowerCase().indexOf('opera')!=-1;

function getElement(layerName,parentLayer)
{
    if( layerobject ) {
        parentLayer = (parentLayer)? parentLayer : self; 
        layerCollection = parentLayer.document.layers;
        if (layerCollection[layerName])
            return layerCollection[layerName];
        for(i=0; i < layerCollection.length;)
            return(getElement(layerName, layerCollection[i++]));
    }
    if( allobject )
        return document.all[layerName];
    if( dom )
        return document.getElementById(layerName);
}

function setContents(layerName, content)
{
    var theLayer = getElement(layerName);
    if( layerobject ) {
        theLayer.document.write(content);
        theLayer.document.close();
        return;
    }
    if (theLayer.innerHTML)
        theLayer.innerHTML = content;
}

var __preloadedImages = new Object();
function preloadImages()
{
    for( i = 0; i < preloadImages.arguments.length; i++ ) {
        if( typeof(preloadImages.arguments[i]) == 'string' ) {
            var x = preloadImages.arguments[i];
    	    __preloadedImages[ x ] = new Image();
	        __preloadedImages[ x ].src = "graphics/" + x;
	    }
	}
}

function toggleAbstract(anchorObject,layerName)
{
    var theLayer = getElement(layerName);
    if( layerobject ) {
        if( !(theLayer.visibility) || theLayer.visibility == 'hide' ) {
            theLayer.visibility = 'show';
            theLayer.left = Math.round( (window.innerWidth - 385) / 2 );
            theLayer.top = anchorObject.y + 20;
        } else
            theLayer.visibility = 'hide';       
    } else {
        if( !(theLayer.style.visibility) || theLayer.style.visibility == 'hidden' ) {
            theLayer.style.visibility = 'visible';
            if( anchorObject.innerHTML )
                anchorObject.innerHTML = 'Hide Abstract';
        } else {
            theLayer.style.visibility = 'hidden';
            if( anchorObject.innerHTML )
                anchorObject.innerHTML = 'Show Abstract';
        }
    }    
    return true;
}

function rollover(imageName)
{
    if( document.images ) {
        var imageURL = document[imageName].src;
        var outPattern = /-out./
        var overPattern = /-over./
        if( outPattern.test(imageURL) )
            document[imageName].src = imageURL.replace( outPattern, '-over.' );
        else if( overPattern.test(imageURL) ) 
            document[imageName].src = imageURL.replace( overPattern, '-out.' );
    }
    return true;
}