function pop_up_picture(imageType,imageName,imageWidth,imageHeight,alt,posLeft,posTop) {
screenh = window.screen.height;
screenw = window.screen.width;
posLeft = (screenw-imageWidth)/2;
posTop = (screenh-imageHeight)/2;
theWindow = window.open("","theWindow","width="+imageWidth+",height="+imageHeight+",scrollbars=no,left="+posLeft+",top="+posTop);
theWindow.document.open();
theWindow.document.write(''+alt+'');
theWindow.document.write('');
theWindow.document.write('
');
theWindow.document.write('');
theWindow.document.close();
theWindow.focus()
}