input[type=file]{
    width:90px;
    color:transparent;
}

window.pressed = function(){
    var a = document.getElementById('aa');
    if(a.value == "")
    {
        fileLabel.innerHTML = "Choose file";
    }
    else
    {
        var theSplit = a.value.split('\');
        fileLabel.innerHTML = theSplit[theSplit.length-1];
    }
};