$("#string").keypress(function (evt) {
            var charCode = (evt.which) ? evt.which : event.keyCode
            if (((charCode <= 93 && charCode >= 65) || (charCode <= 122 && charCode >= 97) || charCode == 8) || charCode == 350 || charCode == 32 || charCode == 351 || charCode == 304 || charCode == 286 || charCode == 287 || charCode == 231 || charCode == 199 || charCode == 305 || charCode == 214 || charCode == 246 || charCode == 220 || charCode == 252) {
                return true;
            }
            return false;
        });