function SF1_isNumber(fs_val, fs_allowable) {
	lb_valid = true;
	li_dotNum = 0;
    if (fs_allowable != "") {
		ls_cmp = "0123456789" + fs_allowable;
	}
	else {
		ls_cmp = "0123456789"
	}

    for (li_i=0; li_i<fs_val.length; li_i++) {
        if (ls_cmp.indexOf(fs_val.charAt(li_i)) < 0) {
            lb_valid = false;
            break;
		}
		if (fs_val.charAt(li_i)==".")
			li_dotNum++;
    }
    
    if (li_dotNum > 1)
		return lb_valid = false;

    return lb_valid;
}