int var1 local
And to assign an initial value, use:
int var1=5 local
The maximum integer is 2,147,483,648. That integer will always be negative. However, one less than that works fine. Go above the maximum integer(maxint), and you get consistent, but worthless, numbers.
The minimum value an integer can have is -2,147,483,648. You get the same problems as going above the maxint if you try to go below the minimum integer.