How can I cancel the dom update

[daystream]

such as
<a4j:poll onbeforedomupdate=" if (somecondition) { return false } " interval="1000"....../>

I want if the somecondition==true then cancel the dom updating.but the code upon couldn't work as i want. It still update the dom.

how can i cancel the dom update.thanks

my english is poor,I hope you can understand what i say.

[daystream]

my mean is
<a4j:poll reRender="someId" onbeforedomupdate=" if (somecondition) { return false } " interval="1000"....../>

the poll still update the "someId" component.

how can i cancel the dom update.thanks