'return a single bar/fader value'

def build_value(self, val, max_dec, sum=0, align=''):

    val = _number_format(val, max_dec)
    if sum:
        sum = _number_format(sum, max_dec)
    value = (('<td    style="' + self.__cssABSVALUES) + '"')
    if align:
        value += ('    align=' + align)
    value += '    nowrap>'
    value += ((('&nbsp;' + self.absValuesPrefix) + str(val)) + self.absValuesSuffix)
    if sum:
        value += ((('    /    ' + self.absValuesPrefix) + str(sum)) + self.absValuesSuffix)
    value += '&nbsp;</td>'
    return value
