var msg = 'Função desativada!';
    //ESSAS SERÃO AS TECLAS DESABILITADAS
    var asciiF2        = 113;
    var asciiF3        = 114;
    var asciiF4        = 115;
    var asciiF5        = 116;
    var asciiF6        = 117;
    var asciiF11        = 122;
    var asciiF12        = 123;
    var asciiF1        = 112;
	var asciiLeftArrow  = 17;
	var asciiRightArrow = 17;
	var asciiBack       = 09;
	var asciiSHIFT      = 16;
	var asciiTab		= 08;
	var asciiHome		= 36;
    
    if(document.all){ //ie has to block in the key down
        document.onkeydown = onKeyPress;
    }else if (document.layers || document.getElementById){ //NS and mozilla have to block in the key press
        document.onkeypress = onKeyPress;
    }
    
    function onKeyPress(evt) {
        window.status = '';
        //get the event object
        var oEvent = (window.event) ? window.event : evt;
      
        //hmmm in mozilla this is jacked, so i have to record these seperate
        //what key was pressed
        var nKeyCode =  oEvent.keyCode ? oEvent.keyCode : oEvent.which ? oEvent.which : void 0;
        var bIsFunctionKey = false;
    
        //hmmm in mozilla the keycode would contain a function key ONLY IF the charcode IS 0  
        //else key code and charcode read funny, the charcode for 't'
        //returns 116, which is the same as the ascii for F5
        //SOOO,... to check if a the keycode is truly a function key,
        //ONLY check when the charcode is null OR 0, IE returns null, mozilla returns 0

        if(oEvent.charCode == null || oEvent.charCode == 0){
            bIsFunctionKey = (nKeyCode >= asciiF1 && nKeyCode <= asciiF12)
        }
      
        //convert the key to a character, makes for more readable code
        var sChar = String.fromCharCode(nKeyCode).toUpperCase();
    
        //get the active tag that has the focus on the page, and its tag type
        var oTarget = (oEvent.target) ? oEvent.target : oEvent.srcElement;
        var sTag = oTarget.tagName.toLowerCase();
        var sTagType = oTarget.getAttribute("type");
      
        var bAltPressed = (oEvent.altKey) ? oEvent.altKey : oEvent.modifiers & 1 > 0;
        var bShiftPressed = (oEvent.shiftKey) ? oEvent.shiftKey : oEvent.modifiers & 4 > 0;
        var bCtrlPressed = (oEvent.ctrlKey) ? oEvent.ctrlKey : oEvent.modifiers & 2 > 0;
        //var bMetaPressed = (oEvent.metaKey) ? oEvent.metaKey : oEvent.modifiers & 8 > 0;
    
        var bRet = true; //assume true as that will be the case most times
        //alert (nKeyCode + ' ' + sChar + ' ' + sTag + ' ' + sTagType + ' ' + bShiftPressed + ' ' + bCtrlPressed + ' ' + bAltPressed);
    
        if(sTagType != null){sTagType = sTagType.toLowerCase();}
    
        //allow these keys inside a text box
        if  (sTag == "textarea" || (sTag == "input" && (sTagType == "text" || sTagType == "password")) && (nKeyCode == asciiBack || nKeyCode == asciiSHIFT || nKeyCode == asciiHome || bShiftPressed || (bCtrlPressed && (nKeyCode == asciiLeftArrow || nKeyCode == asciiRightArrow)))){
            return true;
        } else if(bAltPressed && (nKeyCode == asciiLeftArrow || nKeyCode == asciiRightArrow)){ // block alt + left or right arrow
            bRet = false;
        }else if(bCtrlPressed && (sChar == 'A' || sChar == 'C' || sChar == 'V' || sChar == 'X')){ // ALLOW cut, copy and paste, and SELECT ALL
            bRet = true;
        }else if(bShiftPressed && nKeyCode == asciiTab){//allow shift + tab
            bRet = true;
        }else if(bIsFunctionKey){ // Capture and stop these keys
            bRet = false;
        }else if(bCtrlPressed || bShiftPressed || bAltPressed){ //block ALL other sequences, includes CTRL+O, CTRL+P, CTRL+N, etc....
            bRet = false;
        }
      
        if(!bRet){
            try{
                oEvent.returnValue = false;
                oEvent.cancelBubble = true;
    
                if(document.all){ //IE
                    oEvent.keyCode = 0;
                }else{ //NS
                    oEvent.preventDefault();
                    oEvent.stopPropagation();
                }
                //window.status = msg;
      //alert(msg);
            }catch(ex){
                //alert(msg);
            }
        }
        return bRet;
  }