Dim Value As Long
A Long is a signed 32 bit data type. It can store integer numbers in the range of -2,147,483,648 to 2,147,483,647 and attempting to store a value outside of that range will result in runtime error 6: Overflow.
Note that since a Long matches the width of a pointer in a 32 bit operating system, Longs are commonly used for storing and passing pointers to and from API functions.
The casting function to convert to a Long is
CLng(). For casts from floating point types, the result is rounded to the nearest integer value with .5 rounding up.