File Upload Validation using javascript

Below are the script by which you can validate file when you upload

Make the form

<form>
<div class=”form-level“>Upload Resume
<input name=”image” type=”file” id=”upload_resume” placeholder=”Upload Resume”class=”form-control” /></div>
</form>

var fup = document.getElementById('upload_resume'); 
var fileName = fup.value;
var ext = fileName.substring(fileName.lastIndexOf('.') + 1);
if(ext == "doc" || ext == "docx")
{
return true;
}
else
{
alert("Please select your Resume. Only pdf, doc and docx files are accepted");
fup.value="";
fup.focus();
return false;
}
}