Disabling the form field on submit I have a webform where I've used form alter to do some functionality and validation.

Now in my validation I want to disable a field for a purpose. How can I do so? Is it possible in form validation?
I think what are looking for is hook_node_validate()


  Perform node validation before a node is created or updated.
  
  This hook is invoked from node_validate(), after a user has has
  finished editing the node and is previewing or submitting it. It is
  invoked at the end of all the standard validation steps, and after the
  type-specific hook_validate() is invoked.