/*
 * Disable ctrl + n and other ctrl + key combinations
 * */
function disableCtrlCombinationAndBack(e) {

  var forbiddenKeys = new Array('n','r','p');
  var realEvent;
  var key;
  var isCtrl;
  var isAlt;
  var tagName;
  var isIE;

  if(window.event) {
    //IE
    isIE = true;
    key = event.keyCode;
    tagName = event.srcElement.type;
    realEvent = event;
  }
  else {
    //firefox
    isIE = false;
    key = e.which;
    tagName = e.target.type;
    realEvent = e;
  }

  isCtrl = realEvent.ctrlKey;
  isAlt = realEvent.altKey;



  if(tagName == null)  //if nothing is focused
    tagName = "";

  // block backspace go back function
  if((key == 8 && tagName.toUpperCase() != "TEXT" &&
    tagName.toUpperCase() != "TEXTAREA" && tagName.toUpperCase() != "PASSWORD")) {
    return false;
  }

  // block F5
  if(key == 116) {
    if(isIE) {
      event.keyCode = 0;
      return false;
    }
    else {
      if(realEvent.charCode == null || realEvent.charCode == 0)
        return false;
    }
  }

  // block F11
  if(key == 122) {

    if(isIE) {
      event.keyCode = 0;
      return false;
    }
    else {
      if(realEvent.charCode == null || realEvent.charCode == 0)
        return false;
    }
  }

  // block alternate left/right arrow
  if ((key == 37 || key == 39) && isAlt)
    return false;

  //if ctrl is pressed check if other key is in forbidenKeys array
  if(isCtrl) {
    for(i=0; i<forbiddenKeys.length; i++) {
      //case-insensitive comparation
      if(forbiddenKeys[i].toLowerCase() == String.fromCharCode(key).toLowerCase())
        return false;
    }
  }
  return true;
}

function clickIE4() {
  if (event.button==2) {
    return false;
  }
}

function clickNS4(e) {
  if (document.layers||document.getElementById&&!document.all) {
    if (e.which==2||e.which==3) {
      return false;
    }
  }
}

function hotKey() {
  if (document.layers) {
    document.captureEvents(Event.MOUSEDOWN);
    document.ona=clickNS4;
  }
  else if (document.all&&!document.getElementById) {
    document.ona=clickIE4;
  }

  document.oncontextmenu = new Function("return false")
  if (document.layers)
    document.captureEvents(Event.KEYPRESS)
  document.onkeydown = disableCtrlCombinationAndBack;
  document.ona = disableCtrlCombinationAndBack;
  document.ona = disableCtrlCombinationAndBack;
}
hotKey();



function filterScript(content) {
  if(content == null || content== '')
    return content;
  str = content.replace(/<script([^>])*>/gi, '<script>\/*');
  str = str.replace(/<\/script([^>])*>/gi, '*\/<\/script>');
  return str;
}

//for security issue, don't allow back page from browser.
window.history.forward();
function noBack() { window.history.forward();  }