yes, the expected image is 404.
be careful on how to stitch the tagString as Mark said.
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<div id = 'meinDiv' style="height:500px; width:500px;"></div>
<script>
var text = '{"protagonist":[' +
'{"Nr.": 1,"Country": "Cambodia","Land": "Kambodscha ","Restaurant": "Restaurant Angkor Wat","Adresse": "Paulstraße 22","PLZ": "10557 Berlin","Name": "Dany Hok","Gericht": "Amok Trey","Dish": "Amok Trey","pidr": "8549809","pidp": 22233333,"pidg": 22233333,"Continent": "Asia","Kontinent": "Asien","TeasertextD": "Wenn Sie wissen wollen, wie die Heimat von Dany Hok vom Restaurant Angkor Wat schmeckt, probieren Sie doch das Rezept für Amok Trey aus.","TeasertextE": "Want to taste the cuisine native to Dany Hok of Angkor Wat\'s home? Try this recipe for Amok Trey.","a-d": 37742791,"a-e": 37834756,"Foto-Credits": "Lena Ganssmann"},'+
'{"Nr.": 2,"Country": "Jamaica","Land": "Jamaika ","Restaurant": "Restaurant RosaCaleta","Adresse": "Muskauer Str. 9","PLZ": "10997 Berlin","Name": "Restaurantchef: Kirk Henry, Küchenchef: Troy Lopez","Gericht": "Ackee mit Salzfisch","Dish": "Ackee with saltfish","pidr": 22233333,"pidp": 22233333,"pidg": 22233333,"Continent": "North America","Kontinent": "Nordamerika","TeasertextD": "Wenn Sie wissen wollen, wie die Heimat von Kirk Henry und Troy Lopez vom Restaurant RosaCaleta schmeckt, probieren Sie doch das Rezept für Ackee mit Salzfisch aus.","TeasertextE": "Want to taste the cuisine native to Kirk Henry and Troy Lopez of RosaCaleta\'s home? Try this recipe for Ackee with saltfish.","a-d": 37743413,"a-e": 37834836,"Foto-Credits": "Lena Ganssmann"}]}';
obj = JSON.parse(text);
imgTag = "<img src=\"http://www.dw.com/image/" + obj.protagonist[0].pidr + "_401.jpg\">";
document.getElementById("meinDiv").innerHTML= imgTag;
</script>
</body>
</html>