var bilder = new Array();
			
bilder['fragebogen'] = 'dateien/unterlagen/fragebogen.jpg';
bilder['dvd'] = 'dateien/unterlagen/dvd.jpg';
bilder['buch'] = 'dateien/unterlagen/buch.jpg';
bilder['flyer'] = 'dateien/unterlagen/flyer.jpg';
bilder['www'] = 'dateien/unterlagen/www.jpg';

for(var a=0; a<bilder.length; a++){
	var pic = new Image(100, 25);
	pic.src = bilder[a];
}

function check_produktbild(){
	var datei_id = document.getElementById('unterlage_produktbild').value;
	var max_width = 250;
	var max_height = 250;
	
	if(bilder[datei_id]){
		var img = new Image();
		img.src = bilder[datei_id];
		
		var current_width = img.width;
		var current_height = img.height;
		var new_width = current_width;
		var new_height = current_height;
		
		if(current_width>=current_height){
			if(current_width>max_width){
				new_width = max_width;
				new_height = ((current_height / current_width) * max_width);
			}
		} else {
			if(current_height>max_height){
				new_height = max_height;
				new_width = ((current_width / current_height) * max_height);
			}
		}
		
		document.getElementById('div_unterlage_produktbild').innerHTML = '<img src="'+bilder[datei_id]+'" width="'+new_width+'" height="'+new_height+'" alt=""/>';
	} else {
		document.getElementById('div_unterlage_produktbild').innerHTML = '&nbsp;';
	}
}