CODE EXAMPLE FOR JAVASCRIPT

js get folder of current script

var scripts= document.getElementsByTagName('script');
var path= scripts[scripts.length-1].src.split('?')[0];      // remove any ?query
var mydir= path.split('/').slice(0, -1).join('/')+'/';  // remove last filename part of path

function doSomething() {
    img.src= mydir+'../images/myimage.jpeg';
}