Simple X++ query WHERE clause

Hi,

     I am an X++ beginning programmer.  Can somebody please help me to get my query to run with either of the 2 where clauses(separately of course)?  I want to run the query once to find records with positive amounts and then I want to run it again to find a separate result set of transactions with dates after 1/1/2014.

static void GroupByVendTransWhere(Args _args)

{

VendTrans vendTrans;

;

while select sum(AmountMST) from vendTrans
    group by AccountNum
    // where sum(AmountMST) > 0
    // where TransDate > 01\01\2014

    print vendTrans.AccountNum, " ",vendTrans.AmountMST;

    pause;
}