Can't find MASM's file age - windows

Question

My task:
"Use the GetOpenFileName function to select a file. Check if the age of the file is less than 3 days, execute it. Otherwise, display a dialog box with a question about deleting the file. If the user agrees, wipe."
Problem:
I can't get the age of the file in any way. I'm trying to compare the creationTime returned by GetFileTime with the current time returned by GetSystemTimeAsFileTime. 3 days is (3 * 24 * 60 * 60 * 10000000) 100-ns intervals (FILETIME is measured in such units).
To simplify my task, I compare only the higher parts (dwHighDateTime) of FILETIME structures, the weight of the lower part is 429 seconds, less than 10 minutes.
Something like that:
invoke GetFileTime, hFile, addr ftCreate, NULL, NULL
invoke GetSystemTimeAsFileTime, addr ftNow
mov eax, ftNow.dwHighDateTime
sub eax, ftCreate.dwHighDateTime8
cmp eax, ((3 * 24 * 60 * 60 * 10000000) / 0x100000000)
jg l1
But I get this errors:
;for this: mov eax, ftNow.dwHighDateTime
Third.asm(63) : error A2006: undefined symbol : dwHighDateTime
;for this: cmp eax, ((3 * 24 * 60 * 60 * 10000000) / 0x100000000)
Third.asm(65) : error A2206: missing operator in expression
Help please with this problem.
P.S. If somebody heva another ideas to solve this problem(I mean about age of file), you can recomend it))
File.inc
include WINDOWS.inc
include user32.inc
include kernel32.inc
include comdlg32.inc
includelib user32.lib
includelib kernel32.lib
includelib comdlg32.lib
.data
Time_title db ' Lab_3',0
format db 'More than 3 days. Delete file?', 0
buf db 255 dup(0)
hFile dd 0
readed dd 0
hmem dd 0
File.asm
.386
.model flat,STDCALL
option casemap :none ;case sensitive
include Third.inc
include RADbg.inc
Mem_Alloc PROC Buf_Size:DWORD
add Buf_Size,4
invoke GlobalAlloc,GMEM_MOVEABLE or GMEM_ZEROINIT,Buf_Size
push eax
invoke GlobalLock,eax
pop [eax]
add eax,4
ret
Mem_Alloc endp
Mem_Free PROC DATA:DWORD
mov eax,DATA
sub eax,4
mov eax,[eax]
push eax
push eax
call GlobalUnlock
call GlobalFree
ret
Mem_Free endp
.code
Begin:
call main
invoke ExitProcess,NULL
main proc
LOCAL ftCreate, ftNow: FILETIME;
;LOCAL stUTC, stSysTime: SYSTEMTIME;
invoke Mem_Alloc, 1000h
mov hmem, eax
invoke Mem_Alloc, sizeof OPENFILENAME
mov edi, eax
assume edi: ptr OPENFILENAME
xor eax, eax
mov [edi].lStructSize, sizeof OPENFILENAME
mov [edi].lpstrFile, offset buf
mov [edi].nMaxFile, 255
invoke GetOpenFileName, edi
invoke CreateFile, [edi].lpstrFile, GENERIC_READ,\
FILE_SHARE_READ, NULL, OPEN_EXISTING,\
FILE_ATTRIBUTE_NORMAL, NULL
mov hFile,eax
;invoke GetFileTime, hFile, addr ftCreate, NULL, NULL
;invoke FileTimeToSystemTime, addr ftCreate, addr stSysTime
;invoke GetSystemTime, addr stUTC
invoke GetFileTime, hFile, addr ftCreate, NULL, NULL
invoke GetSystemTimeAsFileTime, addr ftNow
mov eax, ftNow.dwHighDateTime
sub eax, ftCreate.dwHighDateTime
cmp eax, ((3 * 24 * 60 * 60 * 10000000) / 0x100000000)
jg l1
invoke ReadFile, hFile, hmem, 1000h, addr readed, 0
invoke MessageBox, 0, hmem, addr Time_title, MB_OKCANCEL
jmp l2
l1:
invoke MessageBox, 0, addr format, addr Time_title, MB_OKCANCEL
cmp eax, IDOK
jne l2
invoke DeleteFile, addr [edi].lpstrFile
l2:
assume edi: dword
invoke CloseHandle, hFile
invoke Mem_Free, hmem
invoke Mem_Free, edi
ret
main endp
end Begin