workflow event entry not update metadata

hi

wcc 12C is my content

I have a  workflow,  it has   dDocAccount=" " and dSecurityGroup=Public  and  workflow  work  well but   in the  entry events  , i applied  script

<$wfUpdateMetaData("dDocAccount", "Nomi")$>

<$wfUpdateMetaData("dSecurityGroup", "Empl")$>

but not work

not  update  the metadata 

how can i diagnostic  why not update metadata dDocAccount, dSecurityGroup ?

I applied  the same  sentences for other metadata and work..

re