function onlyNumbers(evt) {
	var charCode = (evt.which) ? evt.which : event.keyCode
	if (charCode > 31 && (charCode < 48 || charCode > 57))
		return false;
	return true;
}

function onlyChar(ev) {
	var objEr= /^([A-Za-z0-9_])+$/;
	var key;
	if(window.event){ // IE
		key = ev.keyCode;
	}else if(ev.which){ // Firefox
		key = ev.which;
	}
	var keychar = String.fromCharCode(key);
	return objEr.test(keychar);	
}