function key_number(check) {
	newString = "";
	count = 0;

	if(check.value.length==0) return "";

	for (i = 0; i < check.value.length; i++) {
		ch = check.value.substring(i, i+1);
		if ((ch >= "0") && (ch <= "9")) {
			newString += ch;
		}
	}
	return newString;
}