SEGMENT REPORTING (Details) (USD $)	3 Months Ended		9 Months Ended
	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2013	Jan. 31, 2012	Apr. 30, 2012	Apr. 30, 2011
Revenue	$ 9,515,276	$ 13,122,319	$ 32,901,854	$ 53,493,243
Depreciation and amortization	323,275	455,501	1,005,055	1,336,544
Income (loss) before income taxes from continuing operations	(1,370,832)	(6,076,326)	(1,891,515)	(6,157,115)
Goodwill	1,946,501	1,988,186	1,946,501	1,988,186	1,930,826	2,044,856
Total assets	24,105,064	37,694,451	24,105,064	37,694,451	35,795,399
Additions of property and equipment			1,070,820	338,388
Corporate [Member]
Revenue	0	0	0	0
Depreciation and amortization	6,227	16,536	25,854	49,037
Income (loss) before income taxes from continuing operations	(2,025,446)	(703,255)	(3,923,792)	(2,520,230)
Goodwill	0	0	0	0
Total assets	2,945,478	10,020,278	2,945,478	10,020,278
Additions of property and equipment			0	10,462
Wireless Communication [Member]
Revenue	4,493,003	4,952,998	13,756,591	18,591,536
Depreciation and amortization	85,347	122,874	266,168	377,651
Income (loss) before income taxes from continuing operations	82,839	(739,753)	100,062	384,745
Goodwill	1,946,501	1,988,186	1,946,501	1,988,186
Total assets	7,768,312	9,414,922	7,768,312	9,414,922
Additions of property and equipment			105,525	106,484
Specialty Construction [Member]
Revenue	1,501,020	1,806,619	3,354,660	5,550,177
Depreciation and amortization	182,911	203,561	530,840	571,359
Income (loss) before income taxes from continuing operations	182,627	253,874	294,256	495,900
Goodwill	0	0	0	0
Total assets	8,447,358	7,201,660	8,447,358	7,201,660
Additions of property and equipment			802,423	69,848
Electrical Power [Member]
Revenue	3,521,253	6,362,702	15,790,603	29,351,530
Depreciation and amortization	48,790	112,530	182,193	338,497
Income (loss) before income taxes from continuing operations	389,148	(4,887,192)	1,637,959	(4,517,530)
Goodwill	0	0	0	0
Total assets	4,943,916	11,057,591	4,943,916	11,057,591
Additions of property and equipment			$ 162,872	$ 151,594