js 按键keycode对照
onkeypress是在用户按下并放开任何字母数字键时发生。系统按钮（例如，箭头键和功能键）无法得到识别。
onkeyup 是在用户放开任何先前按下的键盘键时发生。
onkeydown 是在用户按下任何键盘键（包括系统按钮，如箭头键和功能键）时发生。

   currKey=e.keyCode||e.which||e.charCode;
   currKey >=65 && currKey <=90   //非功能键的输入范围

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