In AX 2012 we cannot assign types for dialog fields directly anymore -- only by means of extendedTypeStr precompiled function.
This is how to add a field for keeping int64 values:
DialogField dlgBiggestNum;
int64 theBiggestNumer;
dlgBiggestNum = dlg.addFieldValue(extendedTypeStr(RecId), theBiggestNumer);
This is how to add a field for keeping int64 values:
DialogField dlgBiggestNum;
int64 theBiggestNumer;
dlgBiggestNum = dlg.addFieldValue(extendedTypeStr(RecId), theBiggestNumer);