JAVA & XML & JAVASCRIPT & AJAX & CSS

<script>
function window.onhelp() {//屏蔽F1幫助
return false}
function document.onkeydown() {
?if (event.keyCode==116) {//屏蔽F5鍵
??event.keyCode = 0;
??event.cancelBubble = true;
??return false;
?}
?if (event.keyCode==122) {//屏蔽F11鍵
??event.keyCode = 0;
??event.cancelBubble = true;
??return false;
?}
?if ((event.ctrlKey && event.keyCode==82)) {//屏蔽Ctrl+R
??event.keyCode = 0;
??event.cancelBubble = true;
??return false;
?}
?if ((event.ctrlKey && event.keyCode==78)) {//屏蔽Ctrl+N
??event.keyCode = 0;
??event.cancelBubble = true;
??return false;
?}
?if ((event.keyCode == 8) && (event.srcElement.type != "text" && event.srcElement.type != "textarea" && event.srcElement.type != "password")) {//屏蔽BackSpace鍵
??event.keyCode = 0;
??event.cancelBubble = true;
??return false;
?}
}</script>