function disableCtrlKeyCombination(e)
{
        //list all CTRL + key combinations you want to disable
        var forbiddenKeys = new Array('a', 'n', 'c', 'x', 'v', 'j', '+', '-', '0', window.onmousewheel);
        var allowedKeys = new Array('t', 'n');
        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<allowedKeys.length; i++)
                {
                        //case-insensitive comparation
                        if(allowedKeys[i].toLowerCase() != String.fromCharCode(key).toLowerCase())
                        {
/*
                                alert('Key combination CTRL + '
                                        +String.fromCharCode(key)
                                        +' has been disabled.');
*/
//                                alert('CTRL Key has been disabled.');

								return false;
                        }
                }
        }
        return true;
}