Stupid question I want a char to store values 0 to 255 not characters

[tonnot]

I have a value wich max value is dificcult to value more than 100, so a char is the right type.
But when I use it inside a vector it is not used as numeric but a character and the program chrash.
It is simply:
char my_value;
my_value=98
vector[my_value].....
How I fix this ?
Thanks

[Galik]

Can you post the code that doesn't work?

[tonnot]

Excuse me , I have an assignment a=a=-1; or something like this and there is the problem.....

[Galik]

Unfortunately that's not enough to help us to work out what has gone wrong.