How to find Mandatory fields in any table in AX2012

static void Mandatoryfields_inTable(Args _args)
{

DictTable dictTable;
DictField dictField;
tableId tableId;
fieldId fieldId;
str result;
#DictField
;
dicttable = new DictTable(tablenum(salestable));
for (fieldId = dictTable.fieldNext(0);fieldId;fieldId = dictTable.fieldNext(fieldId))
{
dictField = dictTable.fieldObject(fieldId);

if (!dictField.isSystem() && bitTest(dictField.flags(), #dbf_visible)
&& bitTest(dictField.flags(), #dbf_mandatory))
{
result += dictField.name();
result +='\n';
}
}
info(result);
}