Use check condition (Workflow) for multiple partents

Hi

I have created a custom entity ”Transaltor” and add a N:1 relationship where the primary entity is Task and the related entity is Translator.

I have created a workflowthat changes a custom field from Translator: ”Translator status” value to Unavailable when a new task is created and associated with that translator and a workflow that changes the ”Translator status” value to Available when the Task is market as complete. And two other workflows for the case of cancelling an activity or deleting and activity.

But this is the problem: sometimes more than 1 task is created for the same translator in the same time. When 1 of the 2 tasks is completed, the workflow changes the Translator status to ”Available” although there is still an open task.

How can I make a workflow that checks if there are not other open associated activities before making this change?

Please help me

Thanks,

Adrian