Change user quota via api

Hello
I’m tring to change user quota via api (one.user.quota)… seems that i should send xml or attr. to one.user.quota

i tried:
$str="<USER_QUOTAS><VM_QUOTA>1</VM_QUOTA></USER_QUOTAS>";

but nothing changed in user quota

can you please help ?

I need restrict user - user should not have any change to create more then 1 vm

thx

solved:)
send next xml
$str=‘
VM=[
CPU="-1",
CPU_USED=“1”,
MEMORY="-1",
SYSTEM_DISK_SIZE="-1",
VMS="’.($item_param[“vms”]+$items[“vms”]).’"
]
’;

after creating user