getElementByID("ID").style.backroundImage = url(img) doesnt show in browser

So, I wrote a short script, by which depending on the race the player chooses the backgroundimage is surposed to change:

<<script>>
document.getElementById("map_1").style.backgroundImage= "url(http://something.com/pics/race_" + state.active.variables["race"] + ".png)";
console.log("Javascript sucess. map_1.style.backgroundImage = " + document.getElementById("map_1").style.backgroundImage);
<</script>>

which should change the background image from a div (map_1).
And it even outputs the correct filepath, and it works with normal html/css/js, but the browser doesn´t show any change in the div.
I dont want to change the class, because i would need about 20 different classes then.
Any suggestions?
(Using Sugarcube btw.)