image = new Array(12); 

image[0] = 'januari.jpg' 
image[1] = 'februari.jpg' 
image[2] = 'maart.jpg' 
image[3] = 'april.jpg' 
image[4] = 'mei.jpg' 
image[5] = 'juni.jpg' 
image[6] = 'juli.jpg' 
image[7] = 'augustus.jpg' 
image[8] = 'september.jpg' 
image[9] = 'oktober.jpg' 
image[10] = 'november.jpg' 
image[11] = 'december.jpg' 

        var dt = new Date(); 
        var hr = dt.getMonth(); 
        var msg="<a href='/images/kalender/"+ image[hr] +"' + target=_blank><IMG SRC='/images/kalender/" + image[hr] +"' border='0' width='200' height='131'></a>"; 
        document.write(msg);