function disableBtn(btnID, newText) {

    var btn = document.getElementById(btnID);
    //setTimeout("setImage('" + btnID + "')", 10);
    btn.disabled = true;
    btn.value = newText;
}

//function setImage(btnID) {
//    var btn = document.getElementById(btnID);
//    btn.style.background = 'url(../Images/pdf-icon.jpg)';
//}