Verifies the value in *field* for parameter at index 
        *row*

        :param row: the ith parameter number
        :type row: int
        :param field: detail of the parameter to check
        :type field: str
        :returns: bool -- True if valid

def isFieldValid(self, row, field):
        """Verifies the value in *field* for parameter at index 
        *row*

        :param row: the ith parameter number
        :type row: int
        :param field: detail of the parameter to check
        :type field: str
        :returns: bool -- True if valid
        """
        param = self._parameters[row]
        if param['parameter'] == '':
            return False
        if field == 'nsteps':
            return self.numSteps(row) != 0
        if param['parameter'] == 'filename':
            # do something here... check filenames?
            return True
        if field == 'parameter':
            return True
        # else check that value is between min and max allowed
        return self.checkLimits(row, param[field])