keycode    8 = BackSpace BackSpace
keycode    9 = Tab Tab
keycode   12 = Clear
keycode   13 = Enter
keycode   16 = Shift_L
keycode   17 = Control_L
keycode   18 = Alt_L
keycode   19 = Pause
keycode   20 = Caps_Lock
keycode   27 = Escape Escape
keycode   32 = space space
keycode   33 = Prior
keycode   34 = Next
keycode   35 = End
keycode   36 = Home
keycode   37 = Left
keycode   38 = Up
keycode   39 = Right
keycode   40 = Down
keycode   41 = Select
keycode   42 = Print
keycode   43 = Execute
keycode   45 = Insert
keycode   46 = Delete
keycode   47 = Help
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
keycode   65 = a A
keycode   66 = b B
keycode   67 = c C
keycode   68 = d D
keycode   69 = e E EuroSign
keycode   70 = f F
keycode   71 = g G
keycode   72 = h H
keycode   73 = i I
keycode   74 = j J
keycode   75 = k K
keycode   76 = l L
keycode   77 = m M mu
keycode   78 = n N
keycode   79 = o O
keycode   80 = p P
keycode   81 = q Q at
keycode   82 = r R
keycode   83 = s S
keycode   84 = t T
keycode   85 = u U
keycode   86 = v V
keycode   87 = w W
keycode   88 = x X
keycode   89 = y Y
keycode   90 = z Z
keycode   96 = KP_0 KP_0
keycode   97 = KP_1 KP_1
keycode   98 = KP_2 KP_2
keycode   99 = KP_3 KP_3
keycode 100 = KP_4 KP_4
keycode 101 = KP_5 KP_5
keycode 102 = KP_6 KP_6
keycode 103 = KP_7 KP_7
keycode 104 = KP_8 KP_8
keycode 105 = KP_9 KP_9
keycode 106 = KP_Multiply KP_Multiply
keycode 107 = KP_Add KP_Add
keycode 108 = KP_Separator KP_Separator
keycode 109 = KP_Subtract KP_Subtract
keycode 110 = KP_Decimal KP_Decimal
keycode 111 = KP_Divide KP_Divide
keycode 112 = F1
keycode 113 = F2
keycode 114 = F3
keycode 115 = F4
keycode 116 = F5
keycode 117 = F6
keycode 118 = F7
keycode 119 = F8
keycode 120 = F9
keycode 121 = F10
keycode 122 = F11
keycode 123 = F12
keycode 124 = F13
keycode 125 = F14
keycode 126 = F15
keycode 127 = F16
keycode 128 = F17
keycode 129 = F18
keycode 130 = F19
keycode 131 = F20
keycode 132 = F21
keycode 133 = F22
keycode 134 = F23
keycode 135 = F24
keycode 136 = Num_Lock
keycode 137 = Scroll_Lock
keycode 187 = acute grave
keycode 188 = comma semicolon
keycode 189 = minus underscore
keycode 190 = period colon
keycode 192 = numbersign apostrophe
keycode 210 = plusminus hyphen macron
keycode 211 =
keycode 212 = copyright registered
keycode 213 = guillemotleft guillemotright
keycode 214 = masculine ordfeminine
keycode 215 = ae AE
keycode 216 = cent yen
keycode 217 = questiondown exclamdown
keycode 218 = onequarter onehalf threequarters
keycode 220 = less greater bar
keycode 221 = plus asterisk asciitilde
keycode 227 = multiply division
keycode 228 = acircumflex Acircumflex
keycode 229 = ecircumflex Ecircumflex
keycode 230 = icircumflex Icircumflex
keycode 231 = ocircumflex Ocircumflex
keycode 232 = ucircumflex Ucircumflex
keycode 233 = ntilde Ntilde
keycode 234 = yacute Yacute
keycode 235 = oslash Ooblique
keycode 236 = aring Aring
keycode 237 = ccedilla Ccedilla
keycode 238 = thorn THORN
keycode 239 = eth ETH
keycode 240 = diaeresis cedilla currency
keycode 241 = agrave Agrave atilde Atilde
keycode 242 = egrave Egrave
keycode 243 = igrave Igrave
keycode 244 = ograve Ograve otilde Otilde
keycode 245 = ugrave Ugrave
keycode 246 = adiaeresis Adiaeresis
keycode 247 = ediaeresis Ediaeresis
keycode 248 = idiaeresis Idiaeresis
keycode 249 = odiaeresis Odiaeresis
keycode 250 = udiaeresis Udiaeresis
keycode 251 = ssharp question backslash
keycode 252 = asciicircum degree
keycode 253 = 3 sterling
keycode 254 = Mode_switch
 
使用
<script language="javascript">
     function keyevent(){
     if(event.keyCode==13)
     alert("#$%#%#^^%");
     }
     document.onkeydown = keyevent;
</script>
event.keyCode值為37﹐38﹐39﹐40對應按下的方向鍵分別是 左﹐上﹐右﹐下



"javascript:if (event.keyCode < 45 || event.keyCode > 57) event.returnValue = false;");



if(event.keycode==13)就代表按下的是回车键盘


"javascript:if (event.keyCode > 45 && event.keyCode < 57) event.returnValue = false;");


<html>
<!--//this code by hongseheike-->
<head>
<script language="javascript">
ns4 = (document.layers) ? true : false;
ie4 = (document.all) ? true : false;
function keyDown(e){
if(ns4){
var nkey=e.which;
var iekey='现在是ns浏览器';
var realkey=String.fromCharCode(e.which);
}
if(ie4){
var iekey=event.keyCode;
var nkey='现在是ie浏览器';
var realkey=String.fromCharCode(event.keyCode);
if(event.keyCode==32){realkey='\' 空格\''}
if(event.keyCode==13){realkey='\' 回车\''}
if(event.keyCode==27){realkey='\' Esc\''}
if(event.keyCode==16){realkey='\' Shift\''}
if(event.keyCode==17){realkey='\' Ctrl\''}
if(event.keyCode==18){realkey='\' Alt\''}
}
alert('ns浏览器中键值:'+nkey+'\n'+'ie浏览器中键值:'+iekey+'\n'+'实际键为'+realkey);
}
document.onkeydown = keyDown;
if(ns4){
document.captureEvents(Event.KEYDOWN);}
</script>
</head>
<body>
//Javascript Document
<hr>
<center>
<h3>请按任意一个键。。。。</h3>
</center>
</body>
</html>

**********************************************************************
使用javascript在WEB页面中截获键盘输入
使用event对象的keyCode属性判断输入的键值
eg:if(event.keyCode==13)alert(“enter!”);
键值对应表
A  0X65  U   0X85
B  0X66  V   0X86
C  0X67  W   0X87
D  0X68  X   0X88
E  0X69  Y   0X89
F  0X70  Z   0X90
G  0X71  0   0X48
H  0X72  1   0X49
I  0X73  2   0X50
J  0X74  3   0X51
K  0X75  4   0X52
L  0X76  5   0X53
M  0X77  6   0X54
N  0X78  7   0X55
O  0X79  8   0X56
P  0X80  9   0X57
Q  0X81 ESC  0X1B
R  0X82 CTRL  0X11
S  0X83 SHIFT 0X10
T  0X84 ENTER 0XD

如果要使用组合键,则可以利用event.ctrlKey,event.shiftKey,event .altKey判断是否按下了ctrl键、shift键以及alt键