Using WaitforProperty with dotnet

Hi

I am trying to implement the waitforproperty features using Delphi application but doesn't work. I don't know exactly how the syntax should be:

With _desktop.FormsWindow("CTI Toolkit Agent Desktop (Win32)")

 .WaitForProperty( ("btnNotReady"),True,10000)

.Control("btnHold").WaitForProperty("Enabled",False,1000)

End With

Thanks for your support