Problem with startup CODE

I cannot start up the server with more than 1024M Ram,
@Echo OFF
SET BINDIR=%~dp0
CD /D "%BINDIR%"
"%ProgramFiles(x86)%\Java\jre7\bin\java.exe" -Xmx1024M -Xms1024M -jar craftbukkit.jar
PAUSE
this start up code work fine, but when I tried to increase the ram, it gave me this:
Invalid maximum heap size: -Xmx32000M
The specified size exceeds the maximum representable size.
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

SOLVED thanks for your help guys.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.