she has custody of both kids,i will suggest to my atty ,if she wont test ot tests positive,that i will come after both children if she doesnt get onto some program(this what i did last time to get her in out patient counceling)
Then I think you're going about it all wrong. A contempt citation won't get you what you want.
I would suggest that you file for custody on the grounds that she refused to take a drug test per the judge's orders. While 'innocent until proven guilty' applies in criminal matters, it's going to look very suspicious that she flat out refused a judge's orders.
I would state that you have concerns about drug use and are concerned about the children and would like the judge to give you custody until your ex demonstrates that she is clean - via hair follicle testing. Further, I would ask that periodic hair follicle testing be conducted and if she is found with drugs in her system in the future or if she refuses to take the test that the kids go back to you.
Further, if you have any real evidence that she's using drugs, call child protective services.
Frankly, your focus is misplaced. There is nothing you can do to make her get counseling or treatment. You should be focused on the kids (because it's right and also because that's what's going to convince the court). If you take the position that you want the kids to spend time with their mother, but only if she's clean, that's a positive statement. If, OTOH, you use the custody issue as a battering ram to try to force your ex into counseling, it comes across as controlling and vindictive.
And forget contempt. It won't get you anywhere.