ParseInteger32 PROC

   Converts a signed decimal integer string into 32-bit binary.

Call args:  EDX = offset of signed integer string
            ECX = length of signed integer string

Return arg: EAX = binary value

The Overflow flag is set and an error message is displayed on the console 
if the value cannot be represented as a 32-bit signed integer.

Example:

.data
buffer BYTE "-8193"
bufsize = ($ - buffer)
intval DWORD ?

.code
    mov   edx,OFFSET buffer
    mov   ecx,bufsize
    call  ParseInteger32
    mov   intval,EAX