Allocating more RAM/General Help

The original plan today was to allocate more RAM for my minecraft server.
-Seemed simple enough.-

Computer specs:
Windows 7 computer with 8 GB of RAM.
64 bit system.
I just updated my java to the newest version (1.7 patch 13).


When I currently get onto my server, it says I have 910MB of memory.
I am looking for the correct way to increase this.
I have craftbukkit version 1.4.7-r1.0


I have this in my .bat file
Echo off
"C:\Program Files\Java\jre7\bin\java.exe" -server -Xms2048M -Xmx4096M -jar craftbukkit-1.4.7-R1.0.jar
pause

It still only runs it with 1GB even though I've set a minimum of 2 and a maximum of 4?
What am I doing wrong?
Please help!

 

How did you check your server memory? With Essentials /mem?

 

hmmm, I've been using F3, but what you've mentioned brings up a different number