If you are asking how to reach one variable in one function from the other one, then it is not possible. The scope of the variable is only inside of the block where it is defined. Outside of the block you can't get the value or reach the variable.
The only way is to call the other function and pass the argument by value. This topic has been covered detailly below:
http://www.cplusplus.com/doc/tutorial/functions2/
This is the ultimate resource for c++.
You can also provide the code to get more help about the subject.
