页面滚动条&按键执行事件

判断页面滚动条

$(window).bind('scroll', function () {
            //算出鼠标移动到顶部的高度。
            var scrollt = document.documentElement.scrollTop + document.body.scrollTop;
            if (scrollt > ) {
                $(".return").fadeIn();
                //进行操作。
            } else {
                $(".return").fadeOut();
            }
        })

判断按键

document.onkeydown = function (event) {
var e=event||window.event||arguments.callee.caller.arguments[];
        if (e && e.keyCode == ) {

   }
 }

1 js 里面的键盘事件经常用到，所以收集了键盘事件对应的键码来分享下：
  2 keyCode 8 = BackSpace BackSpace
  3 keyCode 9 = Tab Tab
  4 keyCode 12 = Clear
  5 keyCode 13 = Enter
  6 keyCode 16 = Shift_L
  7 keyCode 17 = Control_L
  8 keyCode 18 = Alt_L
  9 keyCode 19 = Pause
 10 keyCode 20 = Caps_Lock
 11 keyCode 27 = Escape Escape
 12 keyCode 32 = space
 13 keyCode 33 = Prior
 14 keyCode 34 = Next
 15 keyCode 35 = End
 16 keyCode 36 = Home
 17 keyCode 37 = Left
 18 keyCode 38 = Up
 19 keyCode 39 = Right
 20 keyCode 40 = Down
 21 keyCode 41 = Select
 22 keyCode 42 = Print
 23 keyCode 43 = Execute
 24 keyCode 45 = Insert
 25 keyCode 46 = Delete
 26 keyCode 47 = Help
 27 keyCode 48 = 0 equal braceright
 28 keyCode 49 = 1 exclam onesuperior
 29 keyCode 50 = 2 quotedbl twosuperior
 30 keyCode 51 = 3 section threesuperior
 31 keyCode 52 = 4 dollar
 32 keyCode 53 = 5 percent
 33 keyCode 54 = 6 ampersand
 34 keyCode 55 = 7 slash braceleft
 35 keyCode 56 = 8 parenleft bracketleft
 36 keyCode 57 = 9 parenright bracketright
 37 keyCode 65 = a A
 38 keyCode 66 = b B
 39 keyCode 67 = c C
 40 keyCode 68 = d D
 41 keyCode 69 = e E EuroSign
 42 keyCode 70 = f F
 43 keyCode 71 = g G
 44 keyCode 72 = h H
 45 keyCode 73 = i I
 46 keyCode 74 = j J
 47 keyCode 75 = k K
 48 keyCode 76 = l L
 49 keyCode 77 = m M mu
 50 keyCode 78 = n N
 51 keyCode 79 = o O
 52 keyCode 80 = p P
 53 keyCode 81 = q Q at
 54 keyCode 82 = r R
 55 keyCode 83 = s S
 56 keyCode 84 = t T
 57 keyCode 85 = u U
 58 keyCode 86 = v V
 59 keyCode 87 = w W
 60 keyCode 88 = x X
 61 keyCode 89 = y Y
 62 keyCode 90 = z Z
 63 keyCode 96 = KP_0 KP_0
 64 keyCode 97 = KP_1 KP_1
 65 keyCode 98 = KP_2 KP_2
 66 keyCode 99 = KP_3 KP_3
 67 keyCode 100 = KP_4 KP_4
 68 keyCode 101 = KP_5 KP_5
 69 keyCode 102 = KP_6 KP_6
 70 keyCode 103 = KP_7 KP_7
 71 keyCode 104 = KP_8 KP_8
 72 keyCode 105 = KP_9 KP_9
 73 keyCode 106 = KP_Multiply KP_Multiply
 74 keyCode 107 = KP_Add KP_Add
 75 keyCode 108 = KP_Separator KP_Separator
 76 keyCode 109 = KP_Subtract KP_Subtract
 77 keyCode 110 = KP_Decimal KP_Decimal
 78 keyCode 111 = KP_Divide KP_Divide
 79 keyCode 112 = F1
 80 keyCode 113 = F2
 81 keyCode 114 = F3
 82 keyCode 115 = F4
 83 keyCode 116 = F5
 84 keyCode 117 = F6
 85 keyCode 118 = F7
 86 keyCode 119 = F8
 87 keyCode 120 = F9
 88 keyCode 121 = F10
 89 keyCode 122 = F11
 90 keyCode 123 = F12
 91 keyCode 124 = F13
 92 keyCode 125 = F14
 93 keyCode 126 = F15
 94 keyCode 127 = F16
 95 keyCode 128 = F17
 96 keyCode 129 = F18
 97 keyCode 130 = F19
 98 keyCode 131 = F20
 99 keyCode 132 = F21
100 keyCode 133 = F22
101 keyCode 134 = F23
102 keyCode 135 = F24
103 keyCode 136 = Num_Lock
104 keyCode 137 = Scroll_Lock
105 keyCode 187 = acute grave
106 keyCode 188 = comma semicolon
107 keyCode 189 = minus underscore
108 keyCode 190 = period colon
109 keyCode 192 = numbersign apostrophe
110 keyCode 210 = plusminus hyphen macron
111 keyCode 211 =
112 keyCode 212 = copyright registered
113 keyCode 213 = guillemotleft guillemotright
114 keyCode 214 = masculine ordfeminine
115 keyCode 215 = ae AE
116 keyCode 216 = cent yen
117 keyCode 217 = questiondown exclamdown
118 keyCode 218 = onequarter onehalf threequarters
119 keyCode 220 = less greater bar
120 keyCode 221 = plus asterisk asciitilde
121 keyCode 227 = multiply division
122 keyCode 228 = acircumflex Acircumflex
123 keyCode 229 = ecircumflex Ecircumflex
124 keyCode 230 = icircumflex Icircumflex
125 keyCode 231 = ocircumflex Ocircumflex
126 keyCode 232 = ucircumflex Ucircumflex
127 keyCode 233 = ntilde Ntilde
128 keyCode 234 = yacute Yacute
129 keyCode 235 = oslash Ooblique
130 keyCode 236 = aring Aring
131 keyCode 237 = ccedilla Ccedilla
132 keyCode 238 = thorn THORN
133 keyCode 239 = eth ETH
134 keyCode 240 = diaeresis cedilla currency
135 keyCode 241 = agrave Agrave atilde Atilde
136 keyCode 242 = egrave Egrave
137 keyCode 243 = igrave Igrave
138 keyCode 244 = ograve Ograve otilde Otilde
139 keyCode 245 = ugrave Ugrave
140 keyCode 246 = adiaeresis Adiaeresis
141 keyCode 247 = ediaeresis Ediaeresis
142 keyCode 248 = idiaeresis Idiaeresis
143 keyCode 249 = odiaeresis Odiaeresis
144 keyCode 250 = udiaeresis Udiaeresis
145 keyCode 251 = ssharp question backslash
146 keyCode 252 = asciicircum degree
147 keyCode 253 = 3 sterling
148 keyCode 254 = Mode_switch
149 使用event对象的keyCode属性判断输入的键值
150 eg：if(event.keyCode==13)alert(“enter!”);
151 键值对应表
152 A　　0X65 　U 　　0X85
153 B　　0X66　 V　　 0X86
154 C　　0X67　 W　　 0X87
155 D　　0X68　 X 　　0X88
156 E　　0X69　 Y　　 0X89
157 F　　0X70　 Z　　 0X90
158 G　　0X71　 0　　 0X48
159 H　　0X72　 1　　 0X49
160 I　　0X73　 2　　 0X50
161 J　　0X74　 3 　　0X51
162 K　　0X75　 4 　　0X52
163 L　　0X76　 5 　　0X53
164 M　　0X77　 6　　 0X54
165 N　　0X78 　7 　　0X55
166 O　　0X79 　8 　　0X56
167 P　　0X80 　9 　　0X57
168 Q　　0X81　ESC　　0X1B
169 R　　0X82　CTRL 　0X11
170 S　　0X83　SHIFT　0X10
171 T　　0X84　ENTER　0XD
172 如果要使用组合键，则可以判断是否同时按下了这几个键，比如ctrl键、shift键以及alt键的组合使用就可以判断是否多按下了ctrl键、shift键以及alt键