onKeyPress event.keyCode Firefox

Oh and I tried doing a onKeyPress="alert(event.keyCode);" no matter what key i hit when i'm in Firefox, it will show 0 as the value. Any ideas?

IN FireFox it is not keyCode, it is "which":  http://www.quirksmode.org/js/events_properties.html

"which" is a Netscape property.  Try registering the event handler as an anonymous function rather than a string variable.  Also, returnValue is a difficult property to work with.  It's likely the script ultimately won't be fully cross browser if you use it that way.

onkeypress = function (e) {
  if(!e) e=window.event;
  key = e.keycode ? e.keycode : e.which;
  if(key==45) e.returnValue=false;
}


NOTE: For browser event compatibility info go here: http://www.quirksmode.org/dom/w3c_events.html

Uhm. I'm having a little trouble understanding that.

How would I add that to my onKeyPress? Is it in the event with the object that the event belongs with? or is that a function defined elsewhere that i have to do like... onKeyPress="function(window.event.keyCode);" ?

Try This:

Put the following code in a .js file and include it in your html page:
var Keys = {
      BACKSPACE: 8,            TAB: 9,                  ENTER: 13,            SHIFT: 16,
      CTRL: 17,                  ALT: 18,            PAUSE: 19,            CAPS: 20,
      ESC: 27,                   PAGEUP: 33,       PAGEDN: 34,       END: 35,
      HOME: 36,                  LEFT: 37,             UP: 38,             RIGHT: 39,
      DOWN: 40,                  INSERT: 45,       DELETE: 46,       
      n0: 48,      n1: 49, n2: 50, n3: 51, n4: 52,
      n5: 53, n6: 54,      n7: 55,      n8: 56,      n9: 57,
      A:65, B:66, C:67, D:68, E:68, F:70, G:71, H:72, I:73, J:74, K:75,
      L:76, M:77, N:78, O:79, P:80, Q:81, R:82, S:83, T:84, U:85, V:86,
      W:87, X:88, Y:89, Z:90,
      WINLEFT: 91,             WINRIGHT: 92,      SELECT: 93,       NUM0: 96,
      NUM1: 97,                   NUM2: 98,             NUM3: 99,             NUM4: 100,
      NUM5: 101,                   NUM6: 102,             NUM7: 103,             NUM8: 104,
      NUM9: 105,                   MULTIPLY: 106,       ADD: 107,             SUBTRACT: 109,
      DECIMAL: 110,             DIVIDE: 111,       F1: 112,             F2: 113,
      F3: 114,                   F4: 115,            F5: 116,             F6: 117,
      F7: 118,                   F8: 119,             F9: 120,             F10: 121,
      F11: 122,                   F12: 123,             NUMLOCK: 144,       SCROLLLOCK: 145,
      SEMICOLON: 186,       EQUAL: 187,       COMMA: 188,       DASH: 189,
      PERIOD: 190,             FORWARDSLASH: 191,                         GRAVEACCENT: 192,
      OPENBRACKET: 219,       BACKSLASH: 220,                              CLOSEBRACKET: 221,
      QUOTE: 222
};

function KeyPressEvent(eventObj)
{
      this.eventHandler = null;     //the event handler
      this.eventElement = null;     //the element that caused the event
      this.elementTag = "";         //the html tag that caused the event
      this.elementID = "";          //the id of the element
      this.element = null;          //the actual element
      this.keyCode = 0;             //the keycode to capture
      
      if( document.all )
      {
            // IE
            this.eventHandler = eventObj;
            this.eventElement = eventObj.srcElement;
            this.elementTag = eventObj.srcElement.tagName;
            this.elementID = eventObj.srcElement.name;
            this.element = eventObj.srcElement;
            this.keyCode = eventObj.keyCode;
      }
      else
      {
            // Not IE
            this.eventHandler = eventObj;
            this.eventElement = eventObj.target.srcElement;
            this.elementTag = eventObj.target.tagName;
            this.elementID = eventObj.target.name;
            this.element = eventObj.target;
            this.keyCode = eventObj.which;
            
            // Safari bug workaround
            if (this.element.nodeType == 3)
                  targ = targ.parentNode;
      }
}

function KeyHandler()
{
      //register for the event
      if ( document.addEventListener )
            document.addEventListener("keydown", this.keyDown.bind(this), false);
      else if ( document.attachEvent )
            document.attachEvent("onkeydown", this.keyDown.bind(this));
      else
            document.onkeydown = this.keyDown.bind(this);
            
      if (document.layers) document.captureEvents(Event.KEYDOWN);
      
      if ( document.addEventListener )
            document.addEventListener("keyup", this.keyUp.bind(this), false);
      else if ( document.attachEvent )
            document.attachEvent("onkeyup", this.keyUp.bind(this));
      else
            document.onkeyup = this.keyUp.bind(this);
            
      if (document.layers) document.captureEvents(Event.KEYUP);
}

KeyHandler.prototype.keyDown = function(e)
{      
      if ( typeof(this.onKeyDown) != "undefined" )
      {
            if ( !e ) e = window.event;
            var r = this.onKeyDown( new KeyPressEvent(e) );
            
            if ( r == false )
            {
                  if ( window.event ) window.event.cancelBubble = true;
              if ( window.event ) window.event.returnValue = false;
                  if ( e.preventDefault ) e.preventDefault();
              return false;
            }
            else
            {
                  if ( window.event ) window.event.cancelBubble = false;
              if ( window.event ) window.event.returnValue = true;
                  return true;
            }
      }
      else
      {
            alert("No Key Press Event Handler Found!");
      }
};

KeyHandler.prototype.keyUp = function(e)
{      
      if ( typeof(this.onKeyUp) != "undefined" )
      {
            if ( !e ) e = window.event;
            var r = this.onKeyUp( new KeyPressEvent(e) );
            
            if ( r == false )
            {
                  if ( window.event ) window.event.cancelBubble = true;
              if ( window.event ) window.event.returnValue = false;
                  if ( e.preventDefault ) e.preventDefault();
                  if ( e.stopPropagation ) e.stopPropagation();
              return false;
            }
            else
            {
                  if ( window.event ) window.event.cancelBubble = false;
              if ( window.event ) window.event.returnValue = true;
                  return true;
            }
      }
      else
      {
            alert("No Key Press Event Handler Found!");
      }
};


Useage:

var kh = new KeyHandler();
kh.onKeyDown = function(e)  // e is a KeyPressEvent object
{
    if ( e.eventElement == document.getElementById("textbox1") && e.keyCode == 45 )
        return false; //cancel the press
 
    //more information available from e
    e.eventHandler     //the event handler
    e.eventElement      //the element that caused the event
    e.elementTag         //the html tag that caused the event
    e.elementID          //the id of the element
    e.element           //the actual element
    e.keyCode             //the keycode to capture

    return true;
}

kh.onKeyUp = function()
{
   //do nothing
   return true;
}

Hope that helps, Matt

and if you lazy like me, rathe than looking up the keyCode you coud also do this

if ( e.keyCode == Keys.TAB )

:/ uhm, wow, that's a whole ton of code for replacing a single line, that last thing looked quicker. is that assuming you've defined them in the .js file? or do the browsers actually understand the use of the words?

Yea, probally a little overdone, I was using that code for a full blown javascript app :S

netsmithcentral's suggesstion should work fine

lol remind me not to try a full blown javascript app, i would die from a brain shortage.

that short one works :)

NOTE: netsmithcentral's solutions has two typos:
- e must be passed as parameter
- e.keycode is misspelled.

Solution should read:

document.onkeypress = function (e) {
  if(!e) e=window.event;
  key = e.keyCode ? e.keyCode : e.which;
  if(key==45) e.returnValue=false;
}