var refreshperiode=67; 
var webcamframe="http://192.168.178.250/cam.jpg"; 
var hoehe=300; 
var breite=400; 

function refresh(){
document.images["hartl"].src=webcamframe+"?"+new Date();
setTimeout('refresh()', refreshperiode*900);
}

document.write('<img src="'+webcamframe+'" height="'+hoehe+'" width="'+breite+'" name="hartl">');

if(document.images)window.onload=refresh;