How to create a new Number sequence in a new module in Dynamics ax

in Number sequences in Axapta are a mechanism for generating unique numbers. These are generally used as a unique Id to identify a table record.

Every number sequence is linked to an ExtendedDataType inside Axapta. Therefore you will need to create separate datatypes for each number sequence which will be created. 

Follow this doc to know how to create a new Number Sequence

http://dynamicsdx.files.wordpress.com/2010/10/numbersequencex.doc

You can increment the new Number Sequence as following

static void ProformaIdSeq(Args _args)
{
    ExtendedTypeId id = TypeID2ExtendedTypeId(TypeId(Thy_ProformaId));

    NumberSeq num = NumberSeq::newGetNum(NumberSequenceReference::find(id));
    ;

    num.used();  // mark the number as used
    info(num.num());
}

Happy Daxing !