function readTextFile(file){    var rawFile = new XMLHttpRequest();    rawFile.open("GET", file, false);    rawFile.onreadystatechange = function ()    {        if(rawFile.readyState === 4)        {            if(rawFile.status === 200 || rawFile.status == 0)            {                var allText = rawFile.responseText;                alert(allText);            }        }    }    rawFile.send(null);}

readTextFile("file:///C:/dosyadizini/dosya.txt");