Pass current cellview ID to callback of a form

Dear Sir,

I'd like to pass the current cellview ID (when the form displayed) to callback function of the form. So before the form is diaplayed, I use cv = geGetEditCellView() to get the current cellview ID, then I put it into the callback fucntion  ?callback "xpCreateInstArrayCb(hiGetCurrentForm() cv)"

When the form is created with hiCreateAppForm() function, it works well. But if the form is created with hiCreateLayoutForm() function, it can't work. When the callback is triggered, following error is reported:

*Error* eval: unbound variable - cv

Following are the skill code. Please help.

;;Case 1, works well

cv = geGetEditCellView(); Cellview when formXpCreateInstArray is created or displayed.
when( !boundp('formXpCreateInstArray) || (formXpCreateInstArray == nil)

formXpCreateInstArray = hiCreateAppForm(
?name 'formXpCreateInstArray
?formTitle "Create Instance Array"
?fields list(

hiCreateFloatField(
?name 'deviceSpacing
?value 60.0
?prompt "Spacing"
))
?callback "xpCreateInstArrayCb(hiGetCurrentForm() cv)"
?unmapAfterCB t
?buttonLayout 'OKCancelApply
;?dialogStyle 'modal
)

)

;; Case 2, can't work

cv = geGetEditCellView(); Cellview when formXpCreateInstArray is created or displayed.

formXpCreateInstArray = hiCreateLayoutForm(
'formXpCreateInstArray
"Create Instance Array"
hiCreateFormLayout(
'formLayout
?items list(

hiCreateFloatField(
?name 'deviceSpacing
?value 60.0
?prompt "Spacing"
)

))
?callback "xpCreateInstArrayCb(hiGetCurrentForm() cv)"
?unmapAfterCB t
?buttonLayout 'OKCancelApply
;?dialogStyle 'modal
?minSize 400:200
)