Thanks.
Actually it isnt a temprory proterty.
But i have another problem.
And i suppose that thes property is to cause this problem.
I have found the problem yet.
And im dont need to remove thes property.
But i thing it was good when a function like removeproperty() exist.
While i can remove propertys in the form editor manually.
Exuse me for bed english.
Thanks.Again.