The PTR operator 

Working with the Ptr Operator:

Once integer variables have been declared in a program, they can manipulated in the assembly code section of the program.

Assembly instructions require operands to be the same size. However, it may be required at somme point to operate on data in a size other than that originally declared. This can be done with the PTR operator.
For example, the PTR operator can be used to access the high-order word of a DWORD-size variable. The syntax for the PTR operator is:

	type PTR expression

where the PTR operator forces expression to be treated as having the type specified. An example of this use is:

PTR operator
	num DWORD 0
	mov ax, WORD PTR num[0] ;Loads a word-size value from
	mov dx, WORD PTR num[2] ;a doubleword variable