What's wrong?

Hi,

I've created a form with a Library combo field and a layer field. The layers in the layer field is decided by the value of the Library combo field. The code is as following. But there may have some problem. When I close and run it again, Virsuoto will crack. Please help.

procedure(test()
hiCreateLayoutForm(
'formTest
"test"
hiCreateFormLayout(
'layoutMain
?items list(
ddHiCreateLibraryComboField(?name 'lib ?prompt "Library" ?callback lambda((field form)
form->layer->techFile = techGetTechFile(ddGetObj(field->value))
))
leCreateLayerField('layer ?techFile nil ?layerFunction "metal")
)
)
?callback ""
)
hiDisplayForm('formTest)
)