I am having some trouble incrementing a value in a hashtable.

I'm new to C#.

Here's some of the things I tried to do, none of them worked.

myhashtable[mykeys[i]]++; Operator not defined

myInt32 = Int32(myhashtable[mykeys[i]]); class Int32 invalid in context.
myInt32++;

How can i cast the value in my hash table to an integer?

Thanks for any help.