function openimgwindow(jsimg,jswid,jshei,curdesc,fromtop){
positionz = jsimg.lastIndexOf('.jpg');
positiona = jsimg.lastIndexOf('/');
positiona++;
imgname = jsimg.slice(positiona,positionz);
imgname = imgname.replace(/_/g,' ');
newtag = '<p>Click on the image to return to the thumbnails.</p>';
newtag = newtag + '<p><img src="'+jsimg+'" width="'+jswid+'" height="'+jshei+'" alt="" onclick="closeimgwindow()" class="clickable" /></p>';
newtag = newtag + '<p>' + curdesc + '</p>';
document.getElementById('imgholder').innerHTML = newtag;
document.getElementById('imgholder').style.display='block';
document.getElementById('imgholder').style.top=fromtop + 'px';
document.getElementById('main').style.opacity=0.3;
document.getElementById('main').style.filter='alpha(opacity=30)';
}

function closeimgwindow(){
document.getElementById('imgholder').style.display='none';
document.getElementById('main').style.opacity = 1;
document.getElementById('main').style.filter='alpha(opacity=100)';
}