June 30, 2013

December 31, 2012

Costs incurred on uncompleted contracts

$

11,543,541

$

10,733,663

Estimated earnings

10,483,382

9,465,412

22,026,923

20,199,075

Billings to date

(17,778,113

)

(17,944,876

)

$

4,248,810

$

2,254,199

Included in accompanying balance sheets under the following captions:

Costs and estimated earnings in excess of billings on uncompleted contracts

$

4,294,356

$

2,730,104

Billings in excess of costs and estimated earnings on uncompleted contracts

$

(45,546

)

$

(475,905

)