otThreadSetMasterKey() usage

[xiang san]

This function succeeds only when Thread protocols are disabled. my question is: if the Thread protocols are enable,what should I do to disable them  ，now what I do is:

"otThreadSetEnabled(otIns,false);
errornum = otThreadSetMasterKey(otIns,otMasKey);
otThreadSetEnabled(otIns,true);"

but it doesn't work , I need help 

   thanks 

[xiang san]

Dear Jorgen:

I have try it ,it's worked ,thank you very much