JavaScript: how to stop a random number from appearing twice

JavaScript: how to stop a random number from appearing twice

References

Reference NO 1

http://stackoverflow.com/questions/15192614/javascript-how-to-stop-a-random-number-from-appearing-twice

Reference NO 2

http://stackoverflow.com/questions/12435428/preventing-random-operation-from-returning-same-value-twice-in-javascript

Reference NO 3

http://answers.yahoo.com/question/index?qid=20130328052302AAfhHJ3

Reference NO 4

http://bytes.com/topic/php/answers/12656-not-generating-same-random-number-twice

Reference NO 5

http://www.pageresource.com/jscript/jrandom.htm

Reference NO 6

http://www.kirupa.com/html5/advanced_random_numbers_js.htm

Reference NO 7

http://cssglobe.com/simple-way-to-random-display-or-rotate-content-using/

Reference NO 8

http://www.w3schools.com/js/js_obj_math.asp