function disableCtrlKeyCombination(e) {//list all CTRL + key combinations you want to disable
	var forbiddenKeys = new Array('a', 'n', 'c', 'x', 'v', 'j');
	var key;var isCtrl;
	if(window.event){
		key = window.event.keyCode; //IE

		if(window.event.ctrlKey)
			isCtrl = true;
		else
			isCtrl = false;
	}
	else {
		key = e.which; //firefox
		if(e.ctrlKey)
			isCtrl = true;
		else
			isCtrl = false;
	}

	//if ctrl is pressed check if other key is in forbidenKeys array

	if(isCtrl){
		for(i=0; i<forbiddenKeys.length; i++){// alert(forbiddenKeys[i]);
			//case-insensitive comparation
			if(forbiddenKeys[i].toLowerCase() == String.fromCharCode(key).toLowerCase()){// alert(’Key combination CTRL + ‘ +String.fromCharCode(key) +’ has been disabled.’);
				return false;
			}
		}
	}
	return true;
}

function clickIE() {
	if (document.all) return false;
}
if (document.layers) { document.onmousedown=clickNS; }
else { document.oncontextmenu=clickIE; }
document.oncontextmenu=function(){ return false; }; 
function disableselect(e){ return false } 
function reEnable(){return true} 
document.onselectstart=function(){ return false; }; 
if (window.sidebar){ 
document.onmousedown=disableselect;
document.onclick=reEnable;
}
document.oncontextmenu = function(){ return false; }; 
document.onkeypress = function(event) { return disableCtrlKeyCombination(event); };
document.onkeydown = function(event) { return disableCtrlKeyCombination(event); };