<script language="JavaScript">
function dis(){
document.login.button.disabled=true;
return true;
}
function IsDigit(){
return ((event.keyCode >= 48) && (event.keyCode <= 57));
}
</script>
请问这是什么意思吖

document.login.button.disabled=true;

把按钮设置为不可用

下面那个也看不明白

keycode 48 = 0 equal braceright
keycode 49 = 1 exclam onesuperior
keycode 50 = 2 quotedbl twosuperior
keycode 51 = 3 section threesuperior
keycode 52 = 4 dollar
keycode 53 = 5 percent
keycode 54 = 6 ampersand
keycode 55 = 7 slash braceleft
keycode 56 = 8 parenleft bracketleft
keycode 57 = 9 parenright bracketright