Could Anyone Help Me? Please read description

So, i tried to allocate more memory for my minecraft. I usually have 4GB but i put it down for other reasons. This time, when i put the JVm argument to =
-Xmx4G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M, the message in the attached picture comes up on the out put screen? i really need some help.